Myths about evolution in "The Top 10 Myths about Evolution"
John Harshman
10 Myths about Evolution. While it's generally an admirable book, there
are a few problems. Chief among them is that one of their top 10 myths
is no myth.
Myth number 6 is that "people come from monkeys". Smith & Sullivan (S&S)
spend several pages explaining why this is not true. However, I and most
other evolutionary biologists would say that it is true. It all depends
on what you mean by "monkey" -- under some meanings the "myth" is true,
and under others it's false -- so maybe we should explore just what
"monkey" means to S&S, and whether, under their definition, the group
includes any of our ancestors. Unfortunately, S&S are not consistent.
They refer to two different groups as "monkeys": New World monkeys
(Platyrhini) and Old World monkeys (Cercopithecidae). No problem there,
since that's what we usually mean by the word. But then when it comes
time to decide whether we're descended from monkeys, S&S forget about
the existence of NW monkeys entirely; this changes the question to
whether we're descended from OW monkeys. And we are not, so with that
definition, the myth is indeed a myth. But are we allowed to ignore NW
monkeys? It hardly seems as if we should. And the matter then becomes
more complex.
You could avoid an evolutionary definition, and refer only to living
species. Using this definition, we clearly aren't descended from
monkeys, since we are not descended from any living species. S&S don't
do this, since they talk about fossil monkeys.
Or you could restrict the definition to the two groups Cercopithecidae
and Platyrhini. Using this definition, we aren't descended from monkeys
either. But monkeys in that sense aren't really a group at all --
they're two unconnected groups, and the common ancestor of all monkeys
wouldn't be a monkey either. That seems unsatisfactory. (By the way,
using this definition, monkeys are polyphyletic, a bit of biology jargon
referring to any group that doesn't include its most recent common
ancestor.)
One common definition (prevalent up until the rise of cladistics in the
last quarter of the last century) counts monkeys as all anthropoids
(=Platyrhini + Catarhini) except humans and apes. Under that definition,
humans (and apes) are descended from monkeys, but are not monkeys.
(Using this definition, monkeys are paraphyletic, referring to a group
that does include its most recent common ancestor, but doesn't include
all the descendants of that ancestor.)
Under current practice, cladistic practice, monkeys would be synonymous
with anthropoids; not only are humans (and apes) descended from monkeys,
we still are monkeys. (Using this definition, monkeys are monophyletic,
referring to a group that includes its most recent common ancestor and
all the descendants of that ancestor.) That is, there is no monophyletic
group that includes both NW and OW monkeys but doesn't include humans.
There are other problems with the book, some of them fairly trivial,
though they reveal sloppy thinking or editing.
S&S claim (page 92) that the Animal Kingdom includes subkingdoms Metazoa
and Protozoa. A web search shows that this isn't entirely the fault of
S&S, as there are quite a few sites making this claim. But it hasn't
been current biological thought for several decades. "Protozoa" is an
artificial group that is at best paraphyletic, and consists of a wide
variety of single-celled eukaryotes most of which are less closely
related to animals than are fungi.
And under Protozoa, S&S state that there are over 50,000 species of
bacteria. I don't think this was ever current. Bacteria are prokaryotes.
"Protozoans" are eukaryotes.
A little further on we find that Phylum Chordata has a subphylum
Invertebrata. This too is not entirely the fault of S&S, because I find
several references to such a group on the web. But Invertebrata is
another artificial, paraphyletic group. Lancelets are more closely
related to vertebrates than to sea squirts.
In the process of debunking the scala naturae, S&S make the irrelevant
claim that "higher" and "lower" have biological meaning. "Chinese giant
pandas are higher on the phylogenetic tree than Nile crocodiles, in that
their species is a more recent arrival." This is supported by a claim
that "pandas first appeared around 15 million years ago, whereas
crocodiles first appeared around 240 million years ago." This claim
involves a confusion of lineages with species, and of species with more
inclusive clades. In fact we don't know how old the species giant panda
(Ailuropoda melanoleuca) or Nile crocodile (Crocodylus niloticus) are,
and have no good way of finding out. Species don't really translate well
into deep time, because species are defined by their ability to
interbreed, and there's no way to test whether a living population and a
million-year-old population would have interbred. We can produce a
maximum estimate by determining the age of the separation of a lineage
from its most closely related living lineage, but there's no way to
estimate a minimum. I've been unable to determine where the
15-million-year figure for the panda comes from; it may in fact confuse
giant pandas and red pandas, and at any rate reflects not the age of a
species but the age of separation of one lineage from another. Much
worse than that, the figure of 240 million years has nothing to do with
Nile crocodiles, or even the genus Crocodylus, but with the separation
of the remote ancestors of crocodiles from the remote ancestors of
dinosaurs. This is like comparing the age of Genus Homo with the age of
Subclass Metatheria, and using it to claim that the hairy-nosed wombat
is an older species than modern humans.
Now in fact "higher" and "lower" have no meaning, even on the
phylogenetic tree. Giant pandas are no higher or lower on the tree than
are Nile crocodiles, nor in fact, are they any earlier or later, or at
least we have no means to discover that they are. These terms are not
used by modern biologists.
S&S make several other odd claims, including that the fossil record
shows an order of increasing complexity in animals, that the chambered
nautilus is "mussel-like" and has a "simple lensless light-detector" for
an eye, and that lungs evolved from fish swim bladders, for the purpose
of invading terrestrial habitats. Refutation is left as an exercise for
the reader.
The Last Conformist
wrote:
Tangentially, there seems to be a move in popular literature to
redefine Sw. _apa_, which used to mean something like "non-human
anthropoid", to mean "monkey" in the para- or polyphyletic sense.
My nerd rage know no limit.
Ron O
wrote:
> A recent book by Cameron M. Smith and Charles Sullivan is called The Top
> 10 Myths about Evolution. While it's generally an admirable book, there
> are a few problems. Chief among them is that one of their top 10 myths
> is no myth.
>
> Myth number 6 is that "people come from monkeys". Smith & Sullivan (S&S)
> spend several pages explaining why this is not true. However, I and most
> other evolutionary biologists would say that it is true. It all depends
> on what you mean by "monkey" -- under some meanings the "myth" is true,
> and under others it's false -- so maybe we should explore just what
> "monkey" means to S&S, and whether, under their definition, the group
> includes any of our ancestors. Unfortunately, S&S are not consistent.
> They refer to two different groups as "monkeys": New World monkeys
> (Platyrhini) and Old World monkeys (Cercopithecidae). No problem there,
> since that's what we usually mean by the word. But then when it comes
> time to decide whether we're descended from monkeys, S&S forget about
> the existence of NW monkeys entirely; this changes the question to
> whether we're descended from OW monkeys. And we are not, so with that
> definition, the myth is indeed a myth. But are we allowed to ignore NW
> monkeys? It hardly seems as if we should. And the matter then becomes
> more complex.
>
I don't contest your reservations. It all boils down to your
definitions and how you sort things. Our current lineage nests within
the group of anthropoids that we call apes. Our closest ape relatives
are chimps, and there is pretty much no evidence that the chimp human
common ancestor was what science would call a monkey (whether we
consider the group mono or paraphyletic). The common ancestor between
chimps and humans was most likely a brachiating tailless ape. Humans
aren't even close to anyone considering that we came from monkeys
instead of the group we call apes. To have some chance we would need
to branch off somewhere closer to gibbons than to chimps, but we have
the common ancestor with gorilla, then with orangs, and then gibbons
to get through to have that chance. There are at least three other
branch points that we'd have to skip to get to what we call monkeys.
Now, a lot of creationists are ignorant enough to call apes monkeys as
some general name instead of evolutionary relationship. The fact is
that we have never stopped being vertebrates. In that sense we are
still apes, still monkeys, still mammals, still tetrapods, still
vertebrates, still cordates, etc.
Just as a side note the classification of the carcinoma cells
asexually propagated among the tasmanian devils are going to be
classified as what? These seem to be propagated through infection
from one animal to another. They no longer have bones, so are they a
vertebrate lifeform? I'd say yes, but on a strict definition they are
derived from a vertebrate, but they have lost their bones. They are
no longer tetrapods, they don't have mammary glands, they are just
single cells that form tumors. Among lifeforms you can't get much
more retro than being a single cell lifeform. Should they get a new
phyla designation?
Ron Okimoto
John Harshman
Not true, actually. If monkeys are paraphyletic, the chimp/human common
ancestor would be an ape, but not a monkey. By the usual definition,
apes aren't monkeys. Now of course by a cladistic definition, they are,
but in that case monkeys are monophyletic.
> The common ancestor between
> chimps and humans was most likely a brachiating tailless ape. Humans
> aren't even close to anyone considering that we came from monkeys
> instead of the group we call apes.
Here you have contradicted your previous statement. What's up with that?
> To have some chance we would need
> to branch off somewhere closer to gibbons than to chimps, but we have
> the common ancestor with gorilla, then with orangs, and then gibbons
> to get through to have that chance. There are at least three other
> branch points that we'd have to skip to get to what we call monkeys.
> Now, a lot of creationists are ignorant enough to call apes monkeys as
> some general name instead of evolutionary relationship. The fact is
> that we have never stopped being vertebrates. In that sense we are
> still apes, still monkeys, still mammals, still tetrapods, still
> vertebrates, still cordates, etc.
That's the cladistic sense, which is one sense I'm talking about. But I
wasn't talking about the human/chimp common ancestor anyway. You mistake
the question. If our ancestor umpteen branches back was a monkey, we're
descended from monkeys. Doesn't have to be the very first non-human branch.
> Just as a side note the classification of the carcinoma cells
> asexually propagated among the tasmanian devils are going to be
> classified as what? These seem to be propagated through infection
> from one animal to another. They no longer have bones, so are they a
> vertebrate lifeform? I'd say yes, but on a strict definition they are
> derived from a vertebrate, but they have lost their bones. They are
> no longer tetrapods, they don't have mammary glands, they are just
> single cells that form tumors. Among lifeforms you can't get much
> more retro than being a single cell lifeform. Should they get a new
> phyla designation?
No. Once a vertebrate, always a vertebrate. Are snakes tetrapods? In
this particular case, clasification becomes odd. Are these cells even a
species? If so, then is every cancer a new species?
William Morse
A very nice post, that should help clarify the concept of clades. I do
have a few minor quibbles with the following paragraphs.
> Now in fact "higher" and "lower" have no meaning, even on the
> phylogenetic tree. Giant pandas are no higher or lower on the tree than
> are Nile crocodiles, nor in fact, are they any earlier or later, or at
> least we have no means to discover that they are. These terms are not
> used by modern biologists.
True, but you might have gone on to point out that "primitive" and
"derived" are used by modern biologists, but that they refer to
characteristics rather than species. This might help people connect to
the former use of "higher" and "lower" and to understand why those
concepts have disappeared.
> S&S make several other odd claims, including that the fossil record
> shows an order of increasing complexity in animals,
I haven't read the book, so I don't know in what context they are making
this claim. But ISTM there has been an increase in complexity within,
e.g., the vertebrates. The increase is not monotonic, and there should
be no illusion that "more complex" or "more recently evolved" can be
equated with "better". (If anyone asks what the pinnacle of animal
evolution is, my answer is the horsehoe crab.) I do think if you are
critiquing a book about myths, you should be careful not to perpetuate a
myth about there being no increase in complexity. (My claim of an
increase in complexity in vertebrates is based at least partly on
"The Evolution of Vertebrate Design", by Leonard Radinsky. I don't know
that Radinsky makes the claim, but it seems fairly evident to me after
reading about the changes in vertebrate morphology documented in the book)
Yours,
Bill Morse
Walter Bushell
<1b5e1312-6bc6-4a80...@k37g2000hsf.googlegroups.com>,
Ron O <roki...@cox.net> wrote:
> Just as a side note the classification of the carcinoma cells
> asexually propagated among the tasmanian devils are going to be
> classified as what? These seem to be propagated through infection
> from one animal to another. They no longer have bones, so are they a
> vertebrate lifeform? I'd say yes, but on a strict definition they are
> derived from a vertebrate, but they have lost their bones. They are
> no longer tetrapods, they don't have mammary glands, they are just
> single cells that form tumors. Among lifeforms you can't get much
> more retro than being a single cell lifeform. Should they get a new
> phyla designation?
>
> Ron Okimoto
Cladistically they are still tetrapods and mammals.
--
What is done in the heat of battle is (normatively) judged
by different standards than what is leisurely planned in
comfortable conference rooms.
John Harshman
And we tend not to use "primitive" either, exactly because of the
connotation of "not as good". This is one reason why "plesiomorphic" and
"apomorphic" are in common use.
>> S&S make several other odd claims, including that the fossil record
>> shows an order of increasing complexity in animals,
>
> I haven't read the book, so I don't know in what context they are making
> this claim. But ISTM there has been an increase in complexity within,
> e.g., the vertebrates. The increase is not monotonic, and there should
> be no illusion that "more complex" or "more recently evolved" can be
> equated with "better". (If anyone asks what the pinnacle of animal
> evolution is, my answer is the horsehoe crab.) I do think if you are
> critiquing a book about myths, you should be careful not to perpetuate a
> myth about there being no increase in complexity. (My claim of an
> increase in complexity in vertebrates is based at least partly on "The
> Evolution of Vertebrate Design", by Leonard Radinsky. I don't know that
> Radinsky makes the claim, but it seems fairly evident to me after
> reading about the changes in vertebrate morphology documented in the book)
I'm sticking with my story. What increase in complexity? How defined?
Usually it just means "more like us". Is there a more objective measure?
It seems to me that if you wanted to make some kind of case for
increasing complexity, you would have to layer it with a lot of
qualifications.
Now here's what the book says (in Myth 8: Creationism Disproves
Evolution): "When asked to explain the existence of fossils and their
unique layering, many Young Earth Creationists say they're simply the
remains of dead creatures drowned in Noah's flood. But this doesn't
explain why we find the fossils of more complex animals higher in the
rock strata." What do you think that was supposed to mean? I think it's
a version of the scala naturae, which, interestingly, they debunk as Myth 3.
Friar Broccoli
wrote:
> William Morse wrote:
> > I haven't read the book, so I don't know in what context they are making
> > this claim. But ISTM there has been an increase in complexity within,
> > e.g., the vertebrates. The increase is not monotonic, and there should
> > be no illusion that "more complex" or "more recently evolved" can be
> > equated with "better". (If anyone asks what the pinnacle of animal
> > evolution is, my answer is the horsehoe crab.) I do think if you are
> > critiquing a book about myths, you should be careful not to perpetuate a
> > myth about there being no increase in complexity. (My claim of an
> > increase in complexity in vertebrates is based at least partly on "The
> > Evolution of Vertebrate Design", by Leonard Radinsky. I don't know that
> > Radinsky makes the claim, but it seems fairly evident to me after
> > reading about the changes in vertebrate morphology documented in the book)
>
> I'm sticking with my story. What increase in complexity? How defined?
> Usually it just means "more like us". Is there a more objective measure?
How about more parts pasted together in ways that require longer
descriptions?
The most complex thing around at say:
- 1.5 billion years ago was a single cell, or arguably mats of
cooperating cells.
- 0.8 billion years ago was a worm without a nervous system
- 0.6 billion years ago was a worm with a nervous system but
no skeleton
Robert Carnegie
They sound like a new life form, or anyway a separate one,with an
individual biological identity separate from the individual host
although dependent on the host. Parasitic symbiosis.
I believe that sometimes in my life so far, I have emitted viruses,
after being infected - notably, common diseases for which vaccines are
available; measles, mumps, chicken pox - I'm not sure about mumps.
Now, do I have a family relationship with those viruses?
Ron O
wrote:
Isn't that what I said? The chimp/human common ancestor would be an
ape. The paraphyletic part was just about the group we call monkeys
in relation to your presentation of old and new world monkeys as two
distinct groups. Designating a group called apes would make monkeys
paraphyletic because they would be a group composed of multiple
designated groups, but I was just referring to whether there were two
groups of monkeys or not. Apes nest within one of them. It wasn't a
good way to say it, but all I was saying was that the most immediate
common ancestor with chimps and humans was an ape whether we had to
consider old and new world monkeys as one group or two. We already
have a designation (apes) within monkeys that we call something
different.
>
> > The common ancestor between
> > chimps and humans was most likely a brachiating tailless ape. Humans
> > aren't even close to anyone considering that we came from monkeys
> > instead of the group we call apes.
>
> Here you have contradicted your previous statement. What's up with that?
We are simply several branch points away from what we call monkeys.
>
> > To have some chance we would need
> > to branch off somewhere closer to gibbons than to chimps, but we have
> > the common ancestor with gorilla, then with orangs, and then gibbons
> > to get through to have that chance. There are at least three other
> > branch points that we'd have to skip to get to what we call monkeys.
> > Now, a lot of creationists are ignorant enough to call apes monkeys as
> > some general name instead of evolutionary relationship. The fact is
> > that we have never stopped being vertebrates. In that sense we are
> > still apes, still monkeys, still mammals, still tetrapods, still
> > vertebrates, still cordates, etc.
>
> That's the cladistic sense, which is one sense I'm talking about. But I
> wasn't talking about the human/chimp common ancestor anyway. You mistake
> the question. If our ancestor umpteen branches back was a monkey, we're
> descended from monkeys. Doesn't have to be the very first non-human branch.
Going back far enough we are descended from something that we would
call a monkey. We are also descended from something that we would
call a single cell. There are just a whole lot of steps in between.
The guys that use this argument against evolution, don't want to
consider the steps inbetween. They have some fuzzy concept, but they
don't want to face the fact that it isn't just chimps or monkeys that
they have to worry about being descended from, but things like Homo
erectus and archaic Homo sapiens. So no one should just acknowledge
the point that we do, in fact, descend from something that we would
call a monkey without pointing out the failure of the argument. We do
not just descend from monkeys. There are obviously apes in between,
and if we go to the fossils there are other steps.
>
> > Just as a side note the classification of the carcinoma cells
> > asexually propagated among the tasmanian devils are going to be
> > classified as what? These seem to be propagated through infection
> > from one animal to another. They no longer have bones, so are they a
> > vertebrate lifeform? I'd say yes, but on a strict definition they are
> > derived from a vertebrate, but they have lost their bones. They are
> > no longer tetrapods, they don't have mammary glands, they are just
> > single cells that form tumors. Among lifeforms you can't get much
> > more retro than being a single cell lifeform. Should they get a new
> > phyla designation?
>
> No. Once a vertebrate, always a vertebrate. Are snakes tetrapods? In
> this particular case, clasification becomes odd. Are these cells even a
> species? If so, then is every cancer a new species?
Cancers that transfer horizontally through a population and replicate
asexually. Sort of like parthenogenetic nematodes. They could evolve
to infect other species. They just have to evade the immune response
long enough to transfer to another host like a lot of other
parasites. What if they joined up with and got a retrovirus like AIDS
in their genome. Before our ancestors were phyla cordata, what were
they? Not always a cordate, right? Where do new phyla come from? We
aren't going to evolve any more phyla just because someone says so?
Ron Okimoto
John Harshman
All very nice. But the reference is clearly to the Phanerozoic fossil
record. Please explain what makes a Leanchoilia less complex than a Limulus.
John Harshman
Not that I can tell.
> The chimp/human common ancestor would be an
> ape. The paraphyletic part was just about the group we call monkeys
> in relation to your presentation of old and new world monkeys as two
> distinct groups. Designating a group called apes would make monkeys
> paraphyletic
No it wouldn't, any more than designating a group called primates would
make mammals paraphyletic. It's only when you designate mutually
exclusive groups that you cause paraphyly.
> because they would be a group composed of multiple
> designated groups, but I was just referring to whether there were two
> groups of monkeys or not. Apes nest within one of them. It wasn't a
> good way to say it, but all I was saying was that the most immediate
> common ancestor with chimps and humans was an ape whether we had to
> consider old and new world monkeys as one group or two. We already
> have a designation (apes) within monkeys that we call something
> different.
I apparently have no clear idea what you were saying. So I agree that
whatever you were saying, that wasn't a good way to say it. I still
don't know what point you were trying to make.
>>> The common ancestor between
>>> chimps and humans was most likely a brachiating tailless ape. Humans
>>> aren't even close to anyone considering that we came from monkeys
>>> instead of the group we call apes.
>> Here you have contradicted your previous statement. What's up with that?
>
> We are simply several branch points away from what we call monkeys.
How is that relevant to the original question?
I still don't see your point. The "myth" is "people come from monkeys".
People do come from monkeys, as we both agree. So why are we arguing? It
doesn't matter if the most recent common ancestor of chimps and humans
was or was not a monkey. (I say it was, as are we all, but never mind.)
Obviously we come from apes too. And from various other hominids. I
don't think any but the most ignorant creationist (of which there are,
admittedly, several in this newsgroup alone) would claim that the
canonical line of descent goes capuchin -> H. sapiens.
>>> Just as a side note the classification of the carcinoma cells
>>> asexually propagated among the tasmanian devils are going to be
>>> classified as what? These seem to be propagated through infection
>>> from one animal to another. They no longer have bones, so are they a
>>> vertebrate lifeform? I'd say yes, but on a strict definition they are
>>> derived from a vertebrate, but they have lost their bones. They are
>>> no longer tetrapods, they don't have mammary glands, they are just
>>> single cells that form tumors. Among lifeforms you can't get much
>>> more retro than being a single cell lifeform. Should they get a new
>>> phyla designation?
>> No. Once a vertebrate, always a vertebrate. Are snakes tetrapods? In
>> this particular case, clasification becomes odd. Are these cells even a
>> species? If so, then is every cancer a new species?
>
> Cancers that transfer horizontally through a population and replicate
> asexually. Sort of like parthenogenetic nematodes. They could evolve
> to infect other species. They just have to evade the immune response
> long enough to transfer to another host like a lot of other
> parasites. What if they joined up with and got a retrovirus like AIDS
> in their genome. Before our ancestors were phyla cordata, what were
> they? Not always a cordate, right? Where do new phyla come from? We
> aren't going to evolve any more phyla just because someone says so?
Here you implicitly advocate a paraphyletic view of classification,
which I and other modern systematists dislike, for good reasons. Before
our ancestors were chordates, they were deuterostomes, and not members
of any phylum. New phyla do not currently arise. These days, phyla are,
like other groups, supposed to be monophyletic. Since all current
species are assigned to one phylum or another, there's no way for a new
phylum to arise. I should also point out that "phylum" is an arbitrary
designation with no intrinsic meaning.
Steven L.
Not a symbiotic relationship though. Just parasitism.
A better example of parasitic symbiosis is the normal flora--the
"friendly" bacteria (e.g., acidophilus) we carry around in our large
intestines. They outcompete pathogens for nutrients. They even help us
absorb our own nutrients. Mammals are better off with them than if
their guts were sterile.
How did you get infected with them after you were born? When you were a
baby--and your mommy and daddy, who were already infected with them,
kissed you. Or when they took a crap and expelled them into the
environment for other hosts to pick up.
--
Steven L.
Email: sdli...@earthlinkNOSPAM.net
Remove the NOSPAM before replying to me.
Steven L.
Not really, since their genomes don't resemble the human genome. Humans
don't have a "family relationship" with body lice either. They're pure
parasites.
A better "family relationship" is:
"Millions of years ago, a retrovirus infected our primate ancestors,
leaving a legacy of its DNA in their genes. That DNA has been passed
down to humans. A study now finds that the protein encoded by this DNA
abounds in placental cells--suggesting that the protein may play a
useful role today by helping prevent a pregnant woman's immune system
from rejecting her fetus."
http://www.encyclopedia.com/doc/1G1-17408431.html
chris thompson
> Remove the NOSPAM before replying to me.
This is a common terminological error. Parasitism is a form of
symbiosis- which just means "living together", after all. Various
forms of symbiosis exist, including parasitism, in which one partner
benefits at the expense of the other; commensalism, in which one
benefits while the other neither suffers nor gains (think remoras on
sharks); and mutualism (which you're referring to here, obviously) in
which both partners benefit.
Chris
The Last Conformist
[snip]
> Cancers that transfer horizontally through a population and replicate
> asexually. Sort of like parthenogenetic nematodes. They could evolve
> to infect other species. They just have to evade the immune response
> long enough to transfer to another host like a lot of other
> parasites. What if they joined up with and got a retrovirus like AIDS
> in their genome. Before our ancestors were phyla cordata, what were
> they? Not always a cordate, right? Where do new phyla come from? We
> aren't going to evolve any more phyla just because someone says so?
Pragmatically, new phyla are erected when organisms are found that
don't fit in any of the old ones. These particular cells have a very
obvious home in Chordata.
Friar Broccoli
wrote:
You are asking me to compare a Cambrian rock image with a
modern species, so I am necessarily limited to comparing only
those gross features that are analogous, which are not
demonstrably different in complexity.
So you are able to present cases which are unclear, however,
the broad pattern of the fossil record paints a clear, albeit
bumpy, picture of an increasingly high complexity peak with
time.
Is there some reason for believing that the ambiguous evidence
trumps the clear evidence, or that the pattern changed at the
beginning of the Phanerozoic?
Cordially;
Friar Broccoli
Robert Keith Elias, Quebec, Canada Email: EliasRK (of) gmail * com
Best programmer's & all purpose text editor: http://www.semware.com
--------- I consider ALL arguments in support of my views ---------
John Harshman
If you're not comparing fossils to fossils or fossils to modern
organisms, what are you doing?
> So you are able to present cases which are unclear, however,
> the broad pattern of the fossil record paints a clear, albeit
> bumpy, picture of an increasingly high complexity peak with
> time.
>
> Is there some reason for believing that the ambiguous evidence
> trumps the clear evidence, or that the pattern changed at the
> beginning of the Phanerozoic?
What clear evidence? This "increasing complexity" of yours depends on a
single rare event (the origin of multicellularity), one inferred event
(invention of the nervous system) and one nonexistent event (this "worm
without a skeleton, unless you're talking about the vertebrate skeleton,
which doesn't strike me as a clear increase in complexity).
And yes, quite a bit appears to have changed at the beginning of the
Phanerozoic. Can you present evidence for an increase in complexity
during the Phanerozoic? I will grant you that it's likely that the most
complex organism living at any given time has probably increased in
complexity, simply because of diffusion. If that's what you're claiming,
fine. But that doesn't make a general pattern, which is what the quote
claims. This, verbatim, is the myth I'm talking about: "When asked to
explain the existence of fossils and their unique layering, many Young
Earth Creationists say they're simply the remains of dead creatures
drowned in Noah's flood. But this doesn't explain why we find the
fossils of more complex animals higher in the rock strata." Do you want
to defend that claim?
William Morse
I think Robert's complaint is that since there is no way to determine
whether, for example, Leancholia had the same blood chemistry as modern
day Limulus. So these are not a legitimate comparison. What one should
be comparing is the range of Cambrian arthropods with the range of
modern arthropods, and I think if you do this you will see an increase
in complexity.
>> So you are able to present cases which are unclear, however,
>> the broad pattern of the fossil record paints a clear, albeit
>> bumpy, picture of an increasingly high complexity peak with
>> time.
>>
>> Is there some reason for believing that the ambiguous evidence
>> trumps the clear evidence, or that the pattern changed at the
>> beginning of the Phanerozoic?
>
> What clear evidence? This "increasing complexity" of yours depends on a
> single rare event (the origin of multicellularity), one inferred event
> (invention of the nervous system) and one nonexistent event (this "worm
> without a skeleton, unless you're talking about the vertebrate skeleton,
> which doesn't strike me as a clear increase in complexity).
Oh give me a break. Tell me lamprey skeletons are equivalent in
complexity to cichlid skeletons. The complexity measure I am using is
Kolmogorov complexity, which has absolutely zilch to do with how much
they resemble humans.
> And yes, quite a bit appears to have changed at the beginning of the
> Phanerozoic. Can you present evidence for an increase in complexity
> during the Phanerozoic? I will grant you that it's likely that the most
> complex organism living at any given time has probably increased in
> complexity, simply because of diffusion. If that's what you're claiming,
> fine. But that doesn't make a general pattern, which is what the quote
> claims. This, verbatim, is the myth I'm talking about: "When asked to
> explain the existence of fossils and their unique layering, many Young
> Earth Creationists say they're simply the remains of dead creatures
> drowned in Noah's flood. But this doesn't explain why we find the
> fossils of more complex animals higher in the rock strata." Do you want
> to defend that claim?
>
Even Gould, a highly vocal critic of the scala naturae, would defend
that claim. His explanation is the drunkard's walk, but he doesn't deny
the observation of complexity increasing with time. So yes I want to
defend that claim, and I want to see you attack that claim. I want you
to show me mammals from before the K-T that are more complex than
raccoons. I want you to show me Jurassic turtles that are more complex
than leatherbacks. I want you to show me Devonian cephalopods that are
more complex than octopuses.
And then I want you to explain how it could be that the mechanisms of
evolution by natural selection as explained by Darwin could have failed
to produce an increase in complexity over time.
Yours,
Bill Morse
John Harshman
That doesn't hold together. First you say the difference is because we
don't have access to as much data for any given fossil organism as for
any given extant one, and then you say everything is all better if we
compare lots of organisms. But this doesn't change the problem you
initially stated.
And what increase in complexity are you talking about, even when
comparing the full range of diversity?
>>> So you are able to present cases which are unclear, however,
>>> the broad pattern of the fossil record paints a clear, albeit
>>> bumpy, picture of an increasingly high complexity peak with
>>> time.
>>>
>>> Is there some reason for believing that the ambiguous evidence
>>> trumps the clear evidence, or that the pattern changed at the
>>> beginning of the Phanerozoic?
>>
>> What clear evidence? This "increasing complexity" of yours depends on
>> a single rare event (the origin of multicellularity), one inferred
>> event (invention of the nervous system) and one nonexistent event
>> (this "worm without a skeleton, unless you're talking about the
>> vertebrate skeleton, which doesn't strike me as a clear increase in
>> complexity).
>
> Oh give me a break. Tell me lamprey skeletons are equivalent in
> complexity to cichlid skeletons. The complexity measure I am using is
> Kolmogorov complexity, which has absolutely zilch to do with how much
> they resemble humans.
I'd be interested to know how you apply Kolmogorov complexity to
organisms. But I'll agree that lamprey skeletons are simpler than
cichlid skeletons. One for you.
>> And yes, quite a bit appears to have changed at the beginning of the
>> Phanerozoic. Can you present evidence for an increase in complexity
>> during the Phanerozoic? I will grant you that it's likely that the
>> most complex organism living at any given time has probably increased
>> in complexity, simply because of diffusion. If that's what you're
>> claiming, fine. But that doesn't make a general pattern, which is what
>> the quote claims. This, verbatim, is the myth I'm talking about: "When
>> asked to explain the existence of fossils and their unique layering,
>> many Young Earth Creationists say they're simply the remains of dead
>> creatures drowned in Noah's flood. But this doesn't explain why we
>> find the fossils of more complex animals higher in the rock strata."
>> Do you want to defend that claim?
>
> Even Gould, a highly vocal critic of the scala naturae, would defend
> that claim.
This is a safe assertion for you, since we can't ask Gould. But your
characterization below is not what the original quote claims. I will
agree that given a random walk, the most complex animal today is
expected to be more complex than the most complex animal of the
Cambrian. But that doesn't produce a pattern like the one alleged in the
original quote.
> His explanation is the drunkard's walk, but he doesn't deny
> the observation of complexity increasing with time. So yes I want to
> defend that claim, and I want to see you attack that claim. I want you
> to show me mammals from before the K-T that are more complex than
> raccoons.
No, if anything you need to show me mammals from before the K-T that are
less complex than raccoons.
> I want you to show me Jurassic turtles that are more complex
> than leatherbacks. I want you to show me Devonian cephalopods that are
> more complex than octopuses.
Again, that's not the assertion. You need to show that past animals are
less complex than living ones.
> And then I want you to explain how it could be that the mechanisms of
> evolution by natural selection as explained by Darwin could have failed
> to produce an increase in complexity over time.
How would it be expected to produce an increase? Selection doesn't
increase complexity; it optimizes (to the extent it can) organisms for
their immediate environments. You seem to think this will result in a
bias toward increased complexity. That's certainly not your boy Gould's
view. Or mine. Gould is talking about an increase in variance resulting
from a random walk, nothing more.
Robert Carnegie
Put it this way maybe - biological reproductive variation without
natural selection (which is an impossible paradox since some variation
is self-destructive, so there would be /that/ much natural selection)
would still produce added "complexity" by the random walk.
However, it also seems reasonable to suppose that a living thing that
has a more extensive repertoire of interactions with its environment
- a plant that turns to face the sun, that produces antibiotics to
repel bacteria, clever tricks like that - will be favoured by natural
selection, and also is more "complex".
On the other hand, complexity has costs; look at how long your
computer takes to boot up - and how many things there are that can go
wrong.
So that's why humans don't have antlers.
Ernest Major
<e64deb37-bbe9-475c...@y38g2000hsy.googlegroups.com>,
Robert Carnegie <rja.ca...@excite.com> writes
There are many counter-examples. Parasites are commonly derived from,
and are simplified in comparison with, free living ancestors.
>
>On the other hand, complexity has costs; look at how long your
>computer takes to boot up - and how many things there are that can go
>wrong.
>
>So that's why humans don't have antlers.
>
--
alias Ernest Major
Robert Carnegie
> In message
> <e64deb37-bbe9-475c-bf00-49e4be3de...@y38g2000hsy.googlegroups.com>,
> Robert Carnegie <rja.carne...@excite.com> writes
> >Put it this way maybe - biological reproductive variation without
> >natural selection (which is an impossible paradox since some variation
> >is self-destructive, so there would be /that/ much natural selection)
> >would still produce added "complexity" by the random walk.
>
> >However, it also seems reasonable to suppose that a living thing that
> >has a more extensive repertoire of interactions with its environment
> >- a plant that turns to face the sun, that produces antibiotics to
> >repel bacteria, clever tricks like that - will be favoured by natural
> >selection, and also is more "complex".
>
> There are many counter-examples. Parasites are commonly derived from,
> and are simplified in comparison with, free living ancestors.
Good point. Simple organisms work very well, which is why we keep
food in refrigerators - so that bugs don't feast on it too much before
we do. Then again... maybe small /doesn't/ have to mean simple.
As for parasites... we could look for complexity in their relationship
with the host, to avoid getting kicked out. How they resist our
complex immune system.
TomS
<9b78462d-8faa-46c6...@f63g2000hsf.googlegroups.com>, Robert
Carnegie stated..."
I'd suggest looking beyond the complexity of the individual
organism when evaluating the complexity of life. There is
the complexity of the relationships between the individuals
(between individuals of the same species, and between
individuals of different species), and also the complexity
of the relationships between species (the "tree of life").
--
---Tom S.
"As scarce as truth is, the supply has always been in excess of the demand."
attributed to Josh Billings
John Harshman
Phanerozoic? If so, what is your evidence?
TomS
<E_w3k.7282$uE5....@flpi144.ffdc.sbc.com>, John Harshman stated..."
My first reaction to your question is to suggest that there is
no one number that adequately measures the complexity of life.
Ernest Major
<TomS_...@newsguy.com> writes
(with setbacks from mass extinctions) than that there is for a secular
increase in organismal complexity. However, I understand that the book
under discussion claims the latter rather than the former.
--
alias Ernest Major
Friar Broccoli
> In message
> <e64deb37-bbe9-475c-bf00-49e4be3de...@y38g2000hsy.googlegroups.com>,
> Robert Carnegie <rja.carne...@excite.com> writes
> >However, it also seems reasonable to suppose that a living thing that
> >has a more extensive repertoire of interactions with its environment
> >- a plant that turns to face the sun, that produces antibiotics to
> >repel bacteria, clever tricks like that - will be favoured by natural
> >selection, and also is more "complex".
>
> There are many counter-examples. Parasites are commonly derived from,
> and are simplified in comparison with, free living ancestors.
I often wonder if these are "good" counter-examples.
While I certainly don't know the details, it does appear that
when a more "complex" creature from a more demanding
environment starts loosing bits and pieces in order to
(re)occupy a "simpler" environment, it seems to enjoy an
advantage over the creatures that remained in the "simpler"
environment.
It seems that the more demanding (or varied or new) environment
provides the backslider with a range of new tools to use in
the simpler environment. Thus there appears to have been
an increase in complexity, even after the extra bits (like legs
and eyes) have been lost.
I think the movement of land mammals back into the sea
provides a passably good analogy here. They seem to have
done quite well as a result of their improved muscules
and respiration.
Kermit
Heh.
The drunkard's walk explains the intuitive assertion that complexity
has increased after the first single-celled organisms. The first life
of that sort had a few characteristics from which some species would
inevitably (?) diverge. Size is one. Life has certainly gotten bigger
on the average than 1.5 BYA. But there are costs to size. Big species
are not, I think, bigger than they were in the Creataceous. Perhaps
it is also true of the complex species. Difficulty in quantifying
aside... A buddy who ended up as a microbiologist asserted that we
were simpler than lizards. "Oh, sure," he'd say, "our *brains are more
complicated. But they have different sets of enzymes for different
narrow ranges of temperatures. One advantage of our endothermy is that
we could simplify our biochemistry. We only look more complicated
because we are biased to scale."
There may be a few especially complex outliers in the future, but on
the whole perhaps we modern species are about as complicated as we can
get, and have been for a while.
Kermit
John Harshman
Then how can you assert that this thing you can't measure is increasing?
Did you sense a disturbance in the force? Did you see it in a dream?
John Harshman
I don't really see the former either, except for a couple of bumps. One
when life invades the land, and a bit of apparent increase up until the
Permian, when terrestrial ecosystems seem to have assumed more or less
their present nature. I recommend, by the way, a book from U. of Chicago
Press called Terrestrial Ecosystems Through Time. It seems to me that
marine ecosystems haven't changed much in complexity since the Cambrian.
John Harshman
> On Jun 10, 7:46 am, Ernest Major <{$t...@meden.demon.co.uk> wrote:
>> In message
>> <e64deb37-bbe9-475c-bf00-49e4be3de...@y38g2000hsy.googlegroups.com>,
>> Robert Carnegie <rja.carne...@excite.com> writes
>
>>> However, it also seems reasonable to suppose that a living thing that
>>> has a more extensive repertoire of interactions with its environment
>>> - a plant that turns to face the sun, that produces antibiotics to
>>> repel bacteria, clever tricks like that - will be favoured by natural
>>> selection, and also is more "complex".
>> There are many counter-examples. Parasites are commonly derived from,
>> and are simplified in comparison with, free living ancestors.
>
> I often wonder if these are "good" counter-examples.
> While I certainly don't know the details, it does appear that
> when a more "complex" creature from a more demanding
> environment starts loosing bits and pieces in order to
> (re)occupy a "simpler" environment, it seems to enjoy an
> advantage over the creatures that remained in the "simpler"
> environment.
If you don't know the details, how can this "appear" to you? Your one
example is just wrong.
> It seems that the more demanding (or varied or new) environment
> provides the backslider with a range of new tools to use in
> the simpler environment. Thus there appears to have been
> an increase in complexity, even after the extra bits (like legs
> and eyes) have been lost.
>
> I think the movement of land mammals back into the sea
> provides a passably good analogy here. They seem to have
> done quite well as a result of their improved muscules
> and respiration.
>
Nonsense. There are niches for marine air-breathers. They didn't
outcompete fish. They aren't "superior" to the fish. And there have been
marine air-breathers since there were air-breathers.
The Last Conformist
wrote:
> Ernest Major wrote:
> > In message <223108669.00015cbc.033.0...@drn.newsguy.com>, TomS
> > <TomS_mem...@newsguy.com> writes
> >> "On Tue, 10 Jun 2008 07:09:14 -0700 (PDT), in article
That's slightly surprising. Looking at the figures in Bambach, Knoll,
& Sepkoski, "Anatomical and ecological constraints on Phanerozoic
animal diversity in the marine realm", the peak generic diversity of
marine invertebrates in the Cambrian was only about a fifth of that of
the Late Cretaceous (to take an example), and the proportion of
predators much lower. Surely this suggests tighter niche partitioning
and more trophic levels in the Late Cretaceous? And that, presumably,
is what it means for an ecosystem to be more complex?
Mark Isaak
> Friar Broccoli wrote:
>> On Jun 9, 11:53 am, John Harshman <jharshman.diespam...@pacbell.net>
>> wrote:
>>>>[...]
>>> I'm sticking with my story. What increase in complexity? How defined?
>>> Usually it just means "more like us". Is there a more objective
>>> measure?
>>
>> How about more parts pasted together in ways that require longer
>> descriptions?
>>
>> The most complex thing around at say:
>>
>> - 1.5 billion years ago was a single cell, or arguably mats of
>> cooperating cells.
>>
>> - 0.8 billion years ago was a worm without a nervous system
>>
>> - 0.6 billion years ago was a worm with a nervous system but
>> no skeleton
>
> All very nice. But the reference is clearly to the Phanerozoic fossil
> record. Please explain what makes a Leanchoilia less complex than a
> Limulus.
I have seen number of tissue types used before (don't remember where).
I'm not enough of an anatomist, though to quantify Leanchoilia vs.
Limulus.
--
Mark Isaak eciton (at) earthlink (dot) net
"Voice or no voice, the people can always be brought to the bidding of
the leaders. That is easy. All you have to do is tell them they are
being attacked, and denounce the pacifists for lack of patriotism and
exposing the country to danger." -- Hermann Goering
John Harshman
> On Mon, 09 Jun 2008 09:36:28 -0700, John Harshman wrote:
>
>> Friar Broccoli wrote:
>>> On Jun 9, 11:53 am, John Harshman <jharshman.diespam...@pacbell.net>
>>> wrote:
>>>>> [...]
>>>> I'm sticking with my story. What increase in complexity? How defined?
>>>> Usually it just means "more like us". Is there a more objective
>>>> measure?
>>> How about more parts pasted together in ways that require longer
>>> descriptions?
>>>
>>> The most complex thing around at say:
>>>
>>> - 1.5 billion years ago was a single cell, or arguably mats of
>>> cooperating cells.
>>>
>>> - 0.8 billion years ago was a worm without a nervous system
>>>
>>> - 0.6 billion years ago was a worm with a nervous system but
>>> no skeleton
>> All very nice. But the reference is clearly to the Phanerozoic fossil
>> record. Please explain what makes a Leanchoilia less complex than a
>> Limulus.
>
> I have seen number of tissue types used before (don't remember where).
> I'm not enough of an anatomist, though to quantify Leanchoilia vs.
> Limulus.
>
adjustable to fit one's prior prejudices. As I recall, in the
publication that used that criterion, humans were more complex than rats
and both were much more complex than flies. That's a fallacy all its
own. And of course it's impossible to determine the number of tissue
types in a thin carbon film, even if it has 3D structure.
John Harshman
You may be right, though you also need to take into account preservation
bias and provinciality, which I suspect would considerably reduce the
difference. But I agree that it probably wouldn't reduce the difference
enough to explain everything. Marine ecosystems apparently have become
more complex since the Cambrian, probably by the addition of a couple of
trophic levels and a few new guilds. One that comes to mind is the rise
of durophagy, which as far as I know didn't exist then.
Friar Broccoli
Looking at the evidence that is clear. I'm sure you're
familiar with the story of the astronomer who looses his keys
while walking at night. He knows that the only place worth
looking for them is in the lighted areas under street lamps.
You are asking me to consider evidence that is necessarily not
clear. What's the point of that?
>> So you are able to present cases which are unclear, however,
>> the broad pattern of the fossil record paints a clear, albeit
>> bumpy, picture of an increasingly high complexity peak with
>> time.
>> Is there some reason for believing that the ambiguous evidence
>> trumps the clear evidence, or that the pattern changed at the
>> beginning of the Phanerozoic?
.
> What clear evidence? This "increasing complexity" of yours depends on a
> single rare event (the origin of multicellularity),
"Rare" seems like an extremely unreasonable characterization to
me. After all, for cells to get to the point where they could
become multicellular, they had evolve a lot of complex genetic
and other machinery. You know, RNA world (or whatever) through
simple DNA to complex DNA and all the intermediate processes.
> one inferred event (invention of the nervous system)
One inferred event? Once you achieve multicellularity you have
a lot of complex challenges to overcome: tissue differentiation,
developing a body plan, communication and control systems of
which the nervous system is only a part.
> and one nonexistent event (this "worm without a skeleton,
> unless you're talking about the vertebrate skeleton, which
> doesn't strike me as a clear increase in complexity).
Segregating material so it will crystallize in the places you
want it seems like a pretty complicated problem to me. Having a
skeleton to which you can anchor your muscles seems to add
complexity, by [here returning to my proposed definition]
making the required description of a a creature longer. It
certainly adds to the number of tissue types as suggested by
Mark Isaac.
In short, my examples were illustrative, not exhaustive.
To me the increase in complexity over time is so self-evident
that to argue the contrary one must present evidence.
I admit that I haven't been paying close attention to this long
running debate, but so far I have noticed none from you.
> And yes, quite a bit appears to have changed at the beginning
> of the Phanerozoic. Can you present evidence for an increase
> in complexity during the Phanerozoic? I will grant you that
> it's likely that the most complex organism living at any given
> time has probably increased in complexity, simply because of
> diffusion. If that's what you're claiming, fine. But that
> doesn't make a general pattern, which is what the quote
> claims.
For me, arguments about "diffusion" or "random walk" have a
philosophical quality about them, which I have great difficulty
dealing with. The underlying mechanism is random with
selection acting on it. But of course things are really more
complicated than that since there is selection on the
mechanisms for generating "random" variation, but I digress.
Beyond that muddle I'm not sure what to make of all this talk.
As for a case in support of increased complexity since the
beginning of the Phanerozoic. That seems easy enough:
Farther down thread you mentioned that there was an increase in
complexity when plants and animals came on land. We see this
in the more complex skeletal fossils left by both animals and
arthropods/insects. Then insects (and your specialty) birds,
bats and a few others took to the air also adding complexity,
and I'm sure you are (more than I) aware of the increased
complexity of trees over time.
Has it stopped recently? Not as far as I'm aware. Grasses
probably aren't more complex than other plants, but they sure
made things hard on herbivores until they developed double
chambered digestive systems etc. And this is just one example of
the arms race between predators/parasites and prey which drives
increasing complexity, probably as much as new environments do.
> This, verbatim, is the myth I'm talking about: "When asked to
> explain the existence of fossils and their unique layering,
> many Young Earth Creationists say they're simply the remains
> of dead creatures drowned in Noah's flood. But this doesn't
> explain why we find the fossils of more complex animals higher
> in the rock strata." Do you want to defend that claim?
Not really, but since you insist I'll try anyway:
Smith and Sullivan, think that increasing complexity with time
is so self-evident that they use "complexity" as a synonym for
"modern". Well I think "modern" would have been a better
choice of word, but since I agree with them that increasing
complexity is a self-evident inference from the fossil record I
don't see their substitution of the word "complex" as a hanging
offence.
John Harshman
I'm at a loss to figure out what evidence you consider relevant, and why.
>>> So you are able to present cases which are unclear, however,
>>> the broad pattern of the fossil record paints a clear, albeit
>>> bumpy, picture of an increasingly high complexity peak with
>>> time.
>
>>> Is there some reason for believing that the ambiguous evidence
>>> trumps the clear evidence, or that the pattern changed at the
>>> beginning of the Phanerozoic?
>
> .
>
>> What clear evidence? This "increasing complexity" of yours depends on a
>> single rare event (the origin of multicellularity),
>
> "Rare" seems like an extremely unreasonable characterization to
> me. After all, for cells to get to the point where they could
> become multicellular, they had evolve a lot of complex genetic
> and other machinery. You know, RNA world (or whatever) through
> simple DNA to complex DNA and all the intermediate processes.
We are agreed that life began very simply compared to its modern
condition. So?
>> one inferred event (invention of the nervous system)
>
> One inferred event? Once you achieve multicellularity you have
> a lot of complex challenges to overcome: tissue differentiation,
> developing a body plan, communication and control systems of
> which the nervous system is only a part.
But you didn't mention those.
>> and one nonexistent event (this "worm without a skeleton,
>> unless you're talking about the vertebrate skeleton, which
>> doesn't strike me as a clear increase in complexity).
>
> Segregating material so it will crystallize in the places you
> want it seems like a pretty complicated problem to me. Having a
> skeleton to which you can anchor your muscles seems to add
> complexity, by [here returning to my proposed definition]
> making the required description of a a creature longer. It
> certainly adds to the number of tissue types as suggested by
> Mark Isaac.
Is it your claim that vertebrates are more complex than other animals?
I'm really trying to make sense of what you're saying, but you're not
helping me. You seem to be free-associating.
> In short, my examples were illustrative, not exhaustive.
>
> To me the increase in complexity over time is so self-evident
> that to argue the contrary one must present evidence.
> I admit that I haven't been paying close attention to this long
> running debate, but so far I have noticed none from you.
I'm wary of claims that anything is self-evident, and attempts to push
the burden of proof onto the negative.
>> And yes, quite a bit appears to have changed at the beginning
>> of the Phanerozoic. Can you present evidence for an increase
>> in complexity during the Phanerozoic? I will grant you that
>> it's likely that the most complex organism living at any given
>> time has probably increased in complexity, simply because of
>> diffusion. If that's what you're claiming, fine. But that
>> doesn't make a general pattern, which is what the quote
>> claims.
>
> For me, arguments about "diffusion" or "random walk" have a
> philosophical quality about them, which I have great difficulty
> dealing with. The underlying mechanism is random with
> selection acting on it. But of course things are really more
> complicated than that since there is selection on the
> mechanisms for generating "random" variation, but I digress.
> Beyond that muddle I'm not sure what to make of all this talk.
>
> As for a case in support of increased complexity since the
> beginning of the Phanerozoic. That seems easy enough:
>
> Farther down thread you mentioned that there was an increase in
> complexity when plants and animals came on land.
No. An increase in *ecosystem* complexity. That's not what we're talking
about here, which is an increase in organismal complexity. I would be
glad to see your argument that marine animals as a group are less
complex than terrestrial ones, and I certainly can't see it as
"self-evident".
> We see this
> in the more complex skeletal fossils left by both animals and
> arthropods/insects. Then insects (and your specialty) birds,
> bats and a few others took to the air also adding complexity,
> and I'm sure you are (more than I) aware of the increased
> complexity of trees over time.
Again, most of this is ecosystem complexity. Green plants, however, do
seem to offer an example of increase in complexity over time, in the
progression from bryophyte-grade to seed plants. This is more than
diffusion, I think. It involves plants becoming more adapted to purely
terrestrial, even xeric environments, which they do by evolving more
complex structures for support, movement of fluids, and reproduction.
This stands out in the fossil record to me as the only example of
obvious progressive increases in complexity. And of course even that
isn't a general pattern of progress. New groups are added, but older
groups don't go away.
> Has it stopped recently? Not as far as I'm aware.
I would say that it was complete by the Permian.
> Grasses
> probably aren't more complex than other plants, but they sure
> made things hard on herbivores until they developed double
> chambered digestive systems etc.
Given the first part of your sentence, the second part seems irrelevant
to the subject.
> And this is just one example of
> the arms race between predators/parasites and prey which drives
> increasing complexity, probably as much as new environments do.
This is your assertion, which it would be nice for you to support. Why
would we expect arms races to result in increasing complexity, rather
than decreasing or steady complexity?
>> This, verbatim, is the myth I'm talking about: "When asked to
>> explain the existence of fossils and their unique layering,
>> many Young Earth Creationists say they're simply the remains
>> of dead creatures drowned in Noah's flood. But this doesn't
>> explain why we find the fossils of more complex animals higher
>> in the rock strata." Do you want to defend that claim?
>
> Not really, but since you insist I'll try anyway:
I don't insist. I'm asking a question.
> Smith and Sullivan, think that increasing complexity with time
> is so self-evident that they use "complexity" as a synonym for
> "modern". Well I think "modern" would have been a better
> choice of word, but since I agree with them that increasing
> complexity is a self-evident inference from the fossil record I
> don't see their substitution of the word "complex" as a hanging
> offence.
If this is so self-evident, you should have no trouble explaining it.
Please discuss how the general pattern of Phanerozoic animal fossils is
one of increasing complexity over time. Try for clarity.
TomS
<X5z3k.7297$uE5....@flpi144.ffdc.sbc.com>, John Harshman stated..."
I think you misunderstand what I was trying to say.
I was trying to point out that the complexity of life was
not to be measured only by one sort of thing, the
complexity of the individual. Complexity is perhaps a
multi-dimensional thing - if even that is an adequate
characterization.
Robert Carnegie
> "On Tue, 10 Jun 2008 10:46:30 -0700, in article
>
>
>
>
>
>
>
> >TomS wrote:
> >> "On Tue, 10 Jun 2008 08:22:13 -0700, in article
> >>> TomS wrote:
> >>>> "On Tue, 10 Jun 2008 07:09:14 -0700 (PDT), in article
If you have a pack of "Specified Complexity Top Trumps" cards, let's
have a game :-)
(They /do/ publish "Dinosaurs" and "Predators" editions...)
John Harshman
I would say rather that there are many different sorts of complexity,
each of which could be discussed separately. I don't see any point in
jumbling them all together into a single measure. Now what we were
originally talking about was the complexity of individual organisms
(more precisely, animals) and whether it had generally increased during
the Phanerozoic. If there is some other sort of complexity you want to
talk about and/or argue has increased, then go ahead, define it, and
present an argument.
TomS
<EzQ3k.2848$cW3....@nlpi064.nbdc.sbc.com>, John Harshman stated..."
There is no other sort of complexity that I want to talk about
and/or argue has increased.
John Harshman
Are you being unhelpful on purpose? When I talk about the complexity of
individual animals, you bring up other sorts. When I ask about other
sorts, you disclaim interest. Is there something you are trying to talk
about? If so, what is it?
TomS
<hfT3k.7695$mh5....@nlpi067.nbdc.sbc.com>, John Harshman stated..."
What I was trying to talk about is to suggest that it is not
obvious that "complexity" in the world of life can be calculated
by a single number.
John Harshman
Was anyone trying to do that?
Robert Carnegie
I may have come close, by speaking in terms of number of useful
biological responses = complexity, or the same minus "useful".
As far as I recall, the Monkey King as a student of immortality
through magic was told that there are two distinct disciplines of
magical self-transformation, the Thirty-Six and the Seventy-Two, so
which would he like to learn? And he said that seventy-two sounds
like the better value.
But I also acknowledged that an apparently more complex living thing,
such as Britney Spears, can be laid low by a less complex one, such as
a disease germ. Evolutionarily, the germ kind of wins.
William Morse
> William Morse wrote:
>> whether, for example, Leancholia had the same blood chemistry as
>> modern day Limulus. So these are not a legitimate comparison. What one
>> should be comparing is the range of Cambrian arthropods with the range
>> of modern arthropods, and I think if you do this you will see an
>> increase in complexity.
>
> That doesn't hold together. First you say the difference is because we
> don't have access to as much data for any given fossil organism as for
> any given extant one, and then you say everything is all better if we
> compare lots of organisms. But this doesn't change the problem you
> initially stated.
>
> And what increase in complexity are you talking about, even when
> comparing the full range of diversity?
>
>>>> the broad pattern of the fossil record paints a clear, albeit
>>>> bumpy, picture of an increasingly high complexity peak with
>>>> time.
>>>>
>>>> Is there some reason for believing that the ambiguous evidence
>>>> trumps the clear evidence, or that the pattern changed at the
>>>> beginning of the Phanerozoic?
>>>
>>> event (invention of the nervous system) and one nonexistent event
>>> vertebrate skeleton, which doesn't strike me as a clear increase in
>>> complexity).
>>
>> complexity to cichlid skeletons. The complexity measure I am using is
>> Kolmogorov complexity, which has absolutely zilch to do with how much
>> they resemble humans.
>
> I'd be interested to know how you apply Kolmogorov complexity to
> organisms. But I'll agree that lamprey skeletons are simpler than
> cichlid skeletons. One for you.
Actually Kolmogorov complexity ties in quite nicely to evolutionary
biology, since it takes a developmental algorithm to create an organism.
So it is unsurprising that it takes longer to develop complex organisms
than to develop simple organisms - evolution (as opposed to
creationism) has to build on what has gone before. You apparently are
arguing that the upper limit of complexity was already achieved by the
early Phanerozoic.
>>> And yes, quite a bit appears to have changed at the beginning of the
>>> Phanerozoic. Can you present evidence for an increase in complexity
>>> during the Phanerozoic? I will grant you that it's likely that the
>>> most complex organism living at any given time has probably increased
>>> in complexity, simply because of diffusion. If that's what you're
>>> claiming, fine. But that doesn't make a general pattern, which is
>>> what the quote claims. This, verbatim, is the myth I'm talking about:
>>> "When asked to explain the existence of fossils and their unique
>>> layering, many Young Earth Creationists say they're simply the
>>> remains of dead creatures drowned in Noah's flood. But this doesn't
>>> explain why we find the fossils of more complex animals higher in the
>>> rock strata." Do you want to defend that claim?
>>
>> Even Gould, a highly vocal critic of the scala naturae, would defend
>> that claim.
>
> This is a safe assertion for you, since we can't ask Gould. But your
> characterization below is not what the original quote claims. I will
> agree that given a random walk, the most complex animal today is
> expected to be more complex than the most complex animal of the
> Cambrian. But that doesn't produce a pattern like the one alleged in the
> original quote.
We don't have to ask him, we can just read _Full House_, which is
entirely about precisely this question. And the random walk does produce
a pattern of increasing complexity with time. This is the whole point of
_Full House_ - that the increase in complexity with time is not a result
of any "direction" in evolution, not a reflection of a scala naturae,
only a simple result of a random walk from a fixed lower limit of
diversity. But the increase in complexity does exist.
>> His explanation is the drunkard's walk, but he doesn't deny the
>> observation of complexity increasing with time. So yes I want to
>> defend that claim, and I want to see you attack that claim. I want you
>> to show me mammals from before the K-T that are more complex than
>> raccoons.
>
> No, if anything you need to show me mammals from before the K-T that are
> less complex than raccoons.
My knee-jerk reply was all of them. But after doing a small amount of
checking, I don't know that I can defend that statement. One for you.
>> I want you to show me Jurassic turtles that are more complex than
>> leatherbacks. I want you to show me Devonian cephalopods that are
>> more complex than octopuses.
>
> Again, that's not the assertion. You need to show that past animals are
> less complex than living ones.
>
>> And then I want you to explain how it could be that the mechanisms of
>> evolution by natural selection as explained by Darwin could have
>> failed to produce an increase in complexity over time.
>
> How would it be expected to produce an increase? Selection doesn't
> increase complexity; it optimizes (to the extent it can) organisms for
> their immediate environments. You seem to think this will result in a
> bias toward increased complexity. That's certainly not your boy Gould's
> view. Or mine. Gould is talking about an increase in variance resulting
> from a random walk, nothing more.
I agree that is Gould's point - but even that will produce an increase
in complexity with time, which I thought was what you were disputing. I
note that you yourself have cited the increase in diversity of taxa over
time.
Now I am willing to argue for a much more positive bias towards
increasing complexity, and that the increasing complexity would be
expected in both the ecosystems discussed by Ernest Major and the
individual organisms that we have been talking about. One of the
mechanisms that produces an increase in complexity is the Baldwin
effect. Perhaps a more fundamental mechanism is that predicted by
control theory - adding additional feedback loops improves stability,
and more stable systems are more likely to survive perturbations than
less stable systems.
Yours,
Bill Morse
John Harshman
That was a practical question, actually. How do you measure the
Kolmogorov complexity of an animal?
> You apparently are
> arguing that the upper limit of complexity was already achieved by the
> early Phanerozoic.
No. I'm saying that there is no general trend of increasing complexity
in the Phanerozoic fossil record of animals. It's clear that even under
a simple random walk model the most complex animal at any given time is
expected to be more complex than the most complex animal at any previous
time; only some kind of maximum complexity barrier would stop this from
happening, and I'm not arguing that any such barrier has been reached
(though I won't say that it hasn't either).
Only in a particularly narrow sense, that the right tail of the
distribution lengthens over time. But the right tail lengthening would
not produce a pattern in the fossil record, since that tail would
comprise a minuscule fraction of species. Gould offers no support for
the contention.
>>> His explanation is the drunkard's walk, but he doesn't deny the
>>> observation of complexity increasing with time. So yes I want to
>>> defend that claim, and I want to see you attack that claim. I want
>>> you to show me mammals from before the K-T that are more complex than
>>> raccoons.
>>
>> No, if anything you need to show me mammals from before the K-T that
>> are less complex than raccoons.
>
> My knee-jerk reply was all of them. But after doing a small amount of
> checking, I don't know that I can defend that statement. One for you.
Thanks. Is that a general acceptance of my point also regarding turtles,
cephalopods, etc.?
>>> I want you to show me Jurassic turtles that are more complex than
>>> leatherbacks. I want you to show me Devonian cephalopods that are
>>> more complex than octopuses.
>>
>> Again, that's not the assertion. You need to show that past animals
>> are less complex than living ones.
>>
>>> And then I want you to explain how it could be that the mechanisms of
>>> evolution by natural selection as explained by Darwin could have
>>> failed to produce an increase in complexity over time.
>>
>> How would it be expected to produce an increase? Selection doesn't
>> increase complexity; it optimizes (to the extent it can) organisms for
>> their immediate environments. You seem to think this will result in a
>> bias toward increased complexity. That's certainly not your boy
>> Gould's view. Or mine. Gould is talking about an increase in variance
>> resulting from a random walk, nothing more.
>
> I agree that is Gould's point - but even that will produce an increase
> in complexity with time, which I thought was what you were disputing. I
> note that you yourself have cited the increase in diversity of taxa over
> time.
It would produce a slight and hardly measurable increase in the mean (or
modal, or median) complexity. The only noticeable increase would be an
increase in complexity of the maximally complex organism. And this would
not produce a pattern in the fossil record.
> Now I am willing to argue for a much more positive bias towards
> increasing complexity, and that the increasing complexity would be
> expected in both the ecosystems discussed by Ernest Major and the
> individual organisms that we have been talking about. One of the
> mechanisms that produces an increase in complexity is the Baldwin
> effect.
Explain why the Baldwin effect is expected to increase complexity rather
than leave it the same or decrease it. Because I can't immediately see a
rationale.
> Perhaps a more fundamental mechanism is that predicted by
> control theory - adding additional feedback loops improves stability,
> and more stable systems are more likely to survive perturbations than
> less stable systems.
Remembering that we're supposed to be talking about organisms here, not
ecosystems, what exactly is it the stability of that you're talking
about? Do you contend that modern crustaceans have greater stability of
something or other than Cambrian ones?
Really, there is no chance of a general phenomenon here, based on the
history of life. If there were one, it would affect all groups, and
modern jellyfish, e.g., would be more complex than Paleozoic jellyfish.
Do you claim that to be the case?
William Morse
By definition - the shortest program that can uniquely specify the
animal(you already knew that). We can't do this yet, but we are getting
much closer thanks to the efforts of the evo-devo scientists. And unless
one thinks that magic is involved (which neither you nor I do), it is
clearly possible in principle to measure the Kolmogorov complexity of an
animal. Until we do know more about development, we can get a good idea
of the relative complexities of _related_ species on the basis of
comparing features to see the extent of derived vs primitive (I'm
supposed to use the "morphic" terms but I forgot them) features.
Admittedly, until we know a lot more about development it will not be
practical to compare the Kolmogorov complexity of say Drosophila
melanogaster and Acer rubrum.
>> You apparently are
>> arguing that the upper limit of complexity was already achieved by the
>> early Phanerozoic.
>
> No. I'm saying that there is no general trend of increasing complexity
> in the Phanerozoic fossil record of animals. It's clear that even under
> a simple random walk model the most complex animal at any given time is
> expected to be more complex than the most complex animal at any previous
> time; only some kind of maximum complexity barrier would stop this from
> happening, and I'm not arguing that any such barrier has been reached
> (though I won't say that it hasn't either).
I understand your argument, and disagree if you insist on using the
Phanerozoic. I actually would be open to an argument that there is a
complexity "soft" barrier (at least regarding morphological as opposed
to behavioural complexity) that might have been reached.
I did not make myself clear. My statement is that the increase in
complexity does exist as an observable fact. Gould I think might have
accepted this view:
"And yet, undeniably (even for such curmudgeons as me), a basic fact of
the history of life - the basic fact, one might well say - seems to cry
out for progress as the central trend and defining feature of life's
history." (Full House, p. 145) Gould goes on to reject the idea of a
direction in evolution and offers the lengthening right tail
distribution as an alternative.
>>>> His explanation is the drunkard's walk, but he doesn't deny the
>>>> observation of complexity increasing with time. So yes I want to
>>>> defend that claim, and I want to see you attack that claim. I want
>>>> you to show me mammals from before the K-T that are more complex
>>>> than raccoons.
>>>
>>> No, if anything you need to show me mammals from before the K-T that
>>> are less complex than raccoons.
>>
>> My knee-jerk reply was all of them. But after doing a small amount of
>> checking, I don't know that I can defend that statement. One for you.
>
> Thanks. Is that a general acceptance of my point also regarding turtles,
> cephalopods, etc.?
Nope, sorry. After doing again a small amount of checking, it appears
that complex cephalopods such as octopuses, and leatherback turtles
(actually marine turtles in general) only appeared circa 120 million
years ago. They may not be post K-T, but their predecessors do not
exhibit their degree of complexity.
Let's look at beavers as an example. Some proto-beavers learn how to
construct simple dams, enjoy much higher survival rates because of it,
and the dam construction becomes hard-wired (or an increased ability to
learn dam construction does). I suppose you could argue that some other
ability was lost during the hard-wiring process, but it can't be one
that is key to the dam building, and it seems much more likely that the
hard-wiring increases the complexity of the organism.
By the way, I picked the beaver example because I recently encountered a
spectacular beaver dam on a kayak trip. This was a stream that we
could paddle down (well sort of - there was a lot of dragging involved),
and we came on a beaver dam across the entire stream with about a two
foot drop over the dam. Dang but those little rascals are good!
>> Perhaps a more fundamental mechanism is that predicted by control
>> theory - adding additional feedback loops improves stability, and more
>> stable systems are more likely to survive perturbations than less
>> stable systems.
>
> Remembering that we're supposed to be talking about organisms here, not
> ecosystems, what exactly is it the stability of that you're talking
> about? Do you contend that modern crustaceans have greater stability of
> something or other than Cambrian ones?
Yes. Horseshoe crabs have been around forever, but I would be astonished
if modern limulus were not significantly different from ancient limulus.
To suppose otherwise would be to suppose that the existence of sex is an
accident, and that its prevalence is an aberration.
> Really, there is no chance of a general phenomenon here, based on the
> history of life. If there were one, it would affect all groups, and
> modern jellyfish, e.g., would be more complex than Paleozoic jellyfish.
> Do you claim that to be the case?
Remember that there is a well documented increase in biodiversity with
time. There is also an increase in symbiosis and sociality with time (
or are you going to argue that ants and naked mole rats were present in
the early Phanerozoic) I can't say whether modern jellyfish are more
complex than Paleozoic jellyfish ( although I would not be surprised if
they were) - but there is still a trend towards increasing complexity.
Yours,
Bill Morse
John Harshman
I agree. But if you admit that we can't now measure the Kolmogorov
complexity of an animal, how can you assert that this complexity has
increased during the Phanerozoic?
> Until we do know more about development, we can get a good idea
> of the relative complexities of _related_ species on the basis of
> comparing features to see the extent of derived vs primitive (I'm
> supposed to use the "morphic" terms but I forgot them) features.
Apomorphic and plesiomorphic. How? By making the unwarranted assumption
that derived features are more complex than primitive ones? How could
you justify that?
> Admittedly, until we know a lot more about development it will not be
> practical to compare the Kolmogorov complexity of say Drosophila
> melanogaster and Acer rubrum.
Or of any two species, as far as I can see. If you disagree, please
compare the Kolmogorov complexities of Drosophila melanogaster and
Drosophila simulans.
>>> You apparently are
>>> arguing that the upper limit of complexity was already achieved by the
>>> early Phanerozoic.
>>
>> No. I'm saying that there is no general trend of increasing complexity
>> in the Phanerozoic fossil record of animals. It's clear that even
>> under a simple random walk model the most complex animal at any given
>> time is expected to be more complex than the most complex animal at
>> any previous time; only some kind of maximum complexity barrier would
>> stop this from happening, and I'm not arguing that any such barrier
>> has been reached (though I won't say that it hasn't either).
>
> I understand your argument, and disagree if you insist on using the
> Phanerozoic. I actually would be open to an argument that there is a
> complexity "soft" barrier (at least regarding morphological as opposed
> to behavioural complexity) that might have been reached.
If you actually did mean that you disagree, can you give reasons for
your disagreement.
This seems to me more like Darwin's rhetorical practice of making a
claim only to refute it, though I don't have a copy of Full House handy
to check. But if you're agreeing with Gould that any increase is a
right-tail phenomenon, do you also agree with my point, that the fossil
record doesn't display a pattern of increasing complexity during the
Phanerozoic?
>>>>> His explanation is the drunkard's walk, but he doesn't deny the
>>>>> observation of complexity increasing with time. So yes I want to
>>>>> defend that claim, and I want to see you attack that claim. I want
>>>>> you to show me mammals from before the K-T that are more complex
>>>>> than raccoons.
>>>>
>>>> No, if anything you need to show me mammals from before the K-T that
>>>> are less complex than raccoons.
>>>
>>> My knee-jerk reply was all of them. But after doing a small amount of
>>> checking, I don't know that I can defend that statement. One for you.
>>
>> Thanks. Is that a general acceptance of my point also regarding
>> turtles, cephalopods, etc.?
>
> Nope, sorry. After doing again a small amount of checking, it appears
> that complex cephalopods such as octopuses, and leatherback turtles
> (actually marine turtles in general) only appeared circa 120 million
> years ago. They may not be post K-T, but their predecessors do not
> exhibit their degree of complexity.
What is your evidence that octopuses are more complex than previous
cephalopods, or that modern marine turtles are more complex than older
turtles?
I can see how the Baldwin effect could result in an increase in
complexity. The question is how the Baldwin effect would be expected to
result in an increase in complexity. Your faith that traits will never
be lost, only gained, has no obvious justification.
> By the way, I picked the beaver example because I recently encountered a
> spectacular beaver dam on a kayak trip. This was a stream that we could
> paddle down (well sort of - there was a lot of dragging involved), and
> we came on a beaver dam across the entire stream with about a two foot
> drop over the dam. Dang but those little rascals are good!
>>> Perhaps a more fundamental mechanism is that predicted by control
>>> theory - adding additional feedback loops improves stability, and
>>> more stable systems are more likely to survive perturbations than
>>> less stable systems.
>>
>> Remembering that we're supposed to be talking about organisms here,
>> not ecosystems, what exactly is it the stability of that you're
>> talking about? Do you contend that modern crustaceans have greater
>> stability of something or other than Cambrian ones?
>
> Yes. Horseshoe crabs have been around forever, but I would be astonished
> if modern limulus were not significantly different from ancient limulus.
> To suppose otherwise would be to suppose that the existence of sex is an
> accident, and that its prevalence is an aberration.
You will have to explain this somehow. Is sex supposed to be an engine
of increasing complexity? If so, why? And why should modern Limulus
being different from ancient Limulus mean that they were also more
complex? How would you tell? By the way, Limulus isn't a crustacean.
>> Really, there is no chance of a general phenomenon here, based on the
>> history of life. If there were one, it would affect all groups, and
>> modern jellyfish, e.g., would be more complex than Paleozoic
>> jellyfish. Do you claim that to be the case?
>
> Remember that there is a well documented increase in biodiversity with
> time.
How is that relevant?
> There is also an increase in symbiosis and sociality with time (
> or are you going to argue that ants and naked mole rats were present in
> the early Phanerozoic).
No. We don't actually know much about eusociality or lack thereof in the
Cambrian. There were certainly no ants, termites, or mammals; or land
life of any sort beyond bacteria, as far as I know. At any rate, I'm
sure that the right tail of the eusociality curve has extended since the
Cambrian. So?
> I can't say whether modern jellyfish are more
> complex than Paleozoic jellyfish ( although I would not be surprised if
> they were) - but there is still a trend towards increasing complexity.
What trend? And what exactly do you mean when you say "trend"?
William Morse
> William Morse wrote:
>> John Harshman wrote:
(snip)
>>> That was a practical question, actually. How do you measure the
>>> Kolmogorov complexity of an animal?
>>
>> By definition - the shortest program that can uniquely specify the
>> animal(you already knew that). We can't do this yet, but we are
>> getting much closer thanks to the efforts of the evo-devo scientists.
>> And unless one thinks that magic is involved (which neither you nor I
>> do), it is clearly possible in principle to measure the Kolmogorov
>> complexity of an animal.
>
> I agree. But if you admit that we can't now measure the Kolmogorov
> complexity of an animal, how can you assert that this complexity has
> increased during the Phanerozoic?
>
>> Until we do know more about development, we can get a good idea of the
>> relative complexities of _related_ species on the basis of comparing
>> features to see the extent of derived vs primitive (I'm supposed to
>> use the "morphic" terms but I forgot them) features.
>
> Apomorphic and plesiomorphic. How? By making the unwarranted assumption
> that derived features are more complex than primitive ones? How could
> you justify that?
Which is more complex - a sugar cookie, or a chocolate chip cookie? In
order to get to a derived feature we have to develop the primitive
feature, and then add a developmental step (like making sugar cookie
dough and adding chocolate chips). So my statement is rather easy to
justify. In fact the unwarranted assumption is that an apomorphic
feature would be less complex than the plesiomorphic feature from which
it develope. It is possible (in theory one could find a route that
skipped the primitive development) but you would have to prove it. The
assumption in the absence of more detailed information is that the
apomorphic feature is more complex.
>> Admittedly, until we know a lot more about development it will not be
>> practical to compare the Kolmogorov complexity of say Drosophila
>> melanogaster and Acer rubrum.
>
> Or of any two species, as far as I can see. If you disagree, please
> compare the Kolmogorov complexities of Drosophila melanogaster and
> Drosophila simulans.
Give me a detailed list of the differences between the two taxa, and I
will make the comparison.
>>>> You apparently are
>>>> arguing that the upper limit of complexity was already achieved by the
>>>> early Phanerozoic.
>>>
>>> No. I'm saying that there is no general trend of increasing
>>> complexity in the Phanerozoic fossil record of animals. It's clear
>>> that even under a simple random walk model the most complex animal at
>>> any given time is expected to be more complex than the most complex
>>> animal at any previous time; only some kind of maximum complexity
>>> barrier would stop this from happening, and I'm not arguing that any
>>> such barrier has been reached (though I won't say that it hasn't
>>> either).
>>
>> I understand your argument, and disagree if you insist on using the
>> Phanerozoic. I actually would be open to an argument that there is a
>> complexity "soft" barrier (at least regarding morphological as opposed
>> to behavioural complexity) that might have been reached.
>
> If you actually did mean that you disagree, can you give reasons for
> your disagreement.
I have done so and continue to do so. In the meantime, you haven't given
a single counterexample, e.g. a phylum in which there has been a
decrease in complexity during the phanerozoic. In an exchange of
pedantries, my expectation is that I will be informed.
(snip)
>> I did not make myself clear. My statement is that the increase in
>> complexity does exist as an observable fact. Gould I think might have
>> accepted this view:
>>
>> "And yet, undeniably (even for such curmudgeons as me), a basic fact
>> of the history of life - the basic fact, one might well say - seems to
>> cry out for progress as the central trend and defining feature of
>> life's history." (Full House, p. 145) Gould goes on to reject the idea
>> of a direction in evolution and offers the lengthening right tail
>> distribution as an alternative.
>
> This seems to me more like Darwin's rhetorical practice of making a
> claim only to refute it, though I don't have a copy of Full House handy
> to check. But if you're agreeing with Gould that any increase is a
> right-tail phenomenon, do you also agree with my point, that the fossil
> record doesn't display a pattern of increasing complexity during the
> Phanerozoic?
What didn't you understand about "the increase in complexity does exist
as an observable fact"?
>>>>>> His explanation is the drunkard's walk, but he doesn't deny the
>>>>>> observation of complexity increasing with time. So yes I want to
>>>>>> defend that claim, and I want to see you attack that claim. I want
>>>>>> you to show me mammals from before the K-T that are more complex
>>>>>> than raccoons.
>>>>>
>>>>> No, if anything you need to show me mammals from before the K-T
>>>>> that are less complex than raccoons.
>>>>
>>>> My knee-jerk reply was all of them. But after doing a small amount
>>>> of checking, I don't know that I can defend that statement. One for
>>>> you.
>>>
>>> Thanks. Is that a general acceptance of my point also regarding
>>> turtles, cephalopods, etc.?
>>
>> Nope, sorry. After doing again a small amount of checking, it appears
>> that complex cephalopods such as octopuses, and leatherback turtles
>> (actually marine turtles in general) only appeared circa 120 million
>> years ago. They may not be post K-T, but their predecessors do not
>> exhibit their degree of complexity.
>
> What is your evidence that octopuses are more complex than previous
> cephalopods, or that modern marine turtles are more complex than older
> turtles?
The octopuses are universally considered the most intelligent
invertebrates. Since marine turtles didn't exist before 120 million
years ago, they have to be more complex than older marine turtles. There
mere existence shows an increase in complexity among turtles, since they
have successfully invaded a niche they did not previously occupy.
And while we're on that subject, all land animals and plants show an
increase in complexity during the Phanerozoic, since there weren't any
at the beginning of the Phanerozoic.
I have no faith that traits will never be lost, but that does not affect
the argument. The point of the Baldwin effect is that the organism is
the same, save only that the behavior has been genetically added. Now
traits may be lost, but the impact of the Baldwin effect is an increase
in complexity. Unless you argue for an upper bound on complexity (and
you have given no examples or argument for such an upper bound) so that
a trait must be lost when one is gained, there is no reason for the
Baldwin effect to do anything other than increase complexity. The trait
loss is a separate effect that is random, while the Baldwin effect is
directional.
>> By the way, I picked the beaver example because I recently encountered
>> a spectacular beaver dam on a kayak trip. This was a stream that we
>> could paddle down (well sort of - there was a lot of dragging
>> involved), and we came on a beaver dam across the entire stream with
>> about a two foot drop over the dam. Dang but those little rascals are
>> good!
>
>>>> Perhaps a more fundamental mechanism is that predicted by control
>>>> theory - adding additional feedback loops improves stability, and
>>>> more stable systems are more likely to survive perturbations than
>>>> less stable systems.
>>>
>>> Remembering that we're supposed to be talking about organisms here,
>>> not ecosystems, what exactly is it the stability of that you're
>>> talking about? Do you contend that modern crustaceans have greater
>>> stability of something or other than Cambrian ones?
>>
>> Yes. Horseshoe crabs have been around forever, but I would be
>> astonished if modern limulus were not significantly different from
>> ancient limulus. To suppose otherwise would be to suppose that the
>> existence of sex is an accident, and that its prevalence is an
>> aberration.
>
> You will have to explain this somehow. Is sex supposed to be an engine
> of increasing complexity? If so, why? And why should modern Limulus
> being different from ancient Limulus mean that they were also more
> complex? How would you tell? By the way, Limulus isn't a crustacean.
I never said they were. I said that I contend that modern crustaceans
have greater complexity than Cambrian ones, and then I gave a separate
example of an ancient species that shows little morphological change
but is still likely to be different now than when it first appeared. To
respond to your first question, AFAIK the current consensus on sex is
that it persists because it maintains diversity as a response to
parasitism or environmental change or both, If it were possible for an
organism to be perfectly adapted so that no change were necessary
(ancient Limulus being identical to modern Limulus) then sex would have
no purpose.
>>> Really, there is no chance of a general phenomenon here, based on the
>>> history of life. If there were one, it would affect all groups, and
>>> modern jellyfish, e.g., would be more complex than Paleozoic
>>> jellyfish. Do you claim that to be the case?
I didn't note this initially, but the claim that a general phenomenon
would have to affect all groups is a non sequitur. There only has to be
a general increase in complexity among most groups, with no
countervailing decrease in complexity among the remaining groups. Are
you claiming that the jellyfish have decreased in complexity?
>> Remember that there is a well documented increase in biodiversity with
>> time.
>
> How is that relevant?
Unless you want to state that the average complexity per species has
decreased, an increase in number of species times the same average
complexity per species equals an increase in overall complexity.
>> There is also an increase in symbiosis and sociality with time ( or
>> are you going to argue that ants and naked mole rats were present in
>> the early Phanerozoic).
>
> No. We don't actually know much about eusociality or lack thereof in the
> Cambrian. There were certainly no ants, termites, or mammals; or land
> life of any sort beyond bacteria, as far as I know. At any rate, I'm
> sure that the right tail of the eusociality curve has extended since the
> Cambrian. So?
So there has been an increase in complexity.
>> I can't say whether modern jellyfish are more complex than Paleozoic
>> jellyfish ( although I would not be surprised if they were) - but
>> there is still a trend towards increasing complexity.
>
> What trend? And what exactly do you mean when you say "trend"?
>
Well, let's see. There is an increase in skeletal complexity, there is
an increase in individual behavioral complexity (intelligence), there is
an increase in social behavioral complexity, there is an increase in
ecosystem complexity (at least according to Ernest Major), there is an
increase in species diversity, there is an increase in technological
complexity (which we haven't previously discussed). Geez, I don't see
any trend, do you?
I note that you still haven't given any counterargument to the
prediction of increased complexity due to the better control added by
additional feedback loops.
Yours,
Bill Morse
John Harshman
> John Harshman wrote:
>> William Morse wrote:
>>> John Harshman wrote:
>
> (snip)
>
>>>> That was a practical question, actually. How do you measure the
>>>> Kolmogorov complexity of an animal?
>>>
>>> By definition - the shortest program that can uniquely specify the
>>> animal(you already knew that). We can't do this yet, but we are
>>> getting much closer thanks to the efforts of the evo-devo scientists.
>>> And unless one thinks that magic is involved (which neither you nor I
>>> do), it is clearly possible in principle to measure the Kolmogorov
>>> complexity of an animal.
>>
>> I agree. But if you admit that we can't now measure the Kolmogorov
>> complexity of an animal, how can you assert that this complexity has
>> increased during the Phanerozoic?
>>
>>> Until we do know more about development, we can get a good idea of
>>> the relative complexities of _related_ species on the basis of
>>> comparing features to see the extent of derived vs primitive (I'm
>>> supposed to use the "morphic" terms but I forgot them) features.
>>
>> Apomorphic and plesiomorphic. How? By making the unwarranted
>> assumption that derived features are more complex than primitive ones?
>> How could you justify that?
>
> Which is more complex - a sugar cookie, or a chocolate chip cookie?
A chocolate chip cookie, sure. But the rest of your argument doesn't follow.
> In
> order to get to a derived feature we have to develop the primitive
> feature, and then add a developmental step (like making sugar cookie
> dough and adding chocolate chips).
No we don't. This is Haeckel's old law of terminal addition. You should
be aware that it just isn't true.
> So my statement is rather easy to
> justify. In fact the unwarranted assumption is that an apomorphic
> feature would be less complex than the plesiomorphic feature from which
> it develope. It is possible (in theory one could find a route that
> skipped the primitive development) but you would have to prove it. The
> assumption in the absence of more detailed information is that the
> apomorphic feature is more complex.
That may be your assumption. It's certainly not the assumption any
modern biologist would make, and for good reason. Terminal addition is a
false model of evolution.
>>> Admittedly, until we know a lot more about development it will not be
>>> practical to compare the Kolmogorov complexity of say Drosophila
>>> melanogaster and Acer rubrum.
>>
>> Or of any two species, as far as I can see. If you disagree, please
>> compare the Kolmogorov complexities of Drosophila melanogaster and
>> Drosophila simulans.
>
> Give me a detailed list of the differences between the two taxa, and I
> will make the comparison.
How exactly would you do that? But here you go:
http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+melanogaster&db=0
http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+simulans&db=0
Of course most of the differences have no effect on phenotype, if that
matters.
>>>>> You apparently are
>>>>> arguing that the upper limit of complexity was already achieved by the
>>>>> early Phanerozoic.
>>>>
>>>> No. I'm saying that there is no general trend of increasing
>>>> complexity in the Phanerozoic fossil record of animals. It's clear
>>>> that even under a simple random walk model the most complex animal
>>>> at any given time is expected to be more complex than the most
>>>> complex animal at any previous time; only some kind of maximum
>>>> complexity barrier would stop this from happening, and I'm not
>>>> arguing that any such barrier has been reached (though I won't say
>>>> that it hasn't either).
>>>
>>> I understand your argument, and disagree if you insist on using the
>>> Phanerozoic. I actually would be open to an argument that there is a
>>> complexity "soft" barrier (at least regarding morphological as
>>> opposed to behavioural complexity) that might have been reached.
>>
>> If you actually did mean that you disagree, can you give reasons for
>> your disagreement.
>
> I have done so and continue to do so. In the meantime, you haven't given
> a single counterexample, e.g. a phylum in which there has been a
> decrease in complexity during the phanerozoic. In an exchange of
> pedantries, my expectation is that I will be informed.
You misunderstand what a counterexample would look like. It would be a
phylum in which there has been *no increase* in complexity, not a
decrease. And that would refer to no general increase. Some lineages
could have become more complex, others less complex, as long as there
was no general trend. And for that, I would suggest looking at any
phylum at all, with the arguable excpetion of Chordata.
>>> I did not make myself clear. My statement is that the increase in
>>> complexity does exist as an observable fact. Gould I think might have
>>> accepted this view:
>>>
>>> "And yet, undeniably (even for such curmudgeons as me), a basic fact
>>> of the history of life - the basic fact, one might well say - seems
>>> to cry out for progress as the central trend and defining feature of
>>> life's history." (Full House, p. 145) Gould goes on to reject the
>>> idea of a direction in evolution and offers the lengthening right
>>> tail distribution as an alternative.
>>
>> This seems to me more like Darwin's rhetorical practice of making a
>> claim only to refute it, though I don't have a copy of Full House
>> handy to check. But if you're agreeing with Gould that any increase is
>> a right-tail phenomenon, do you also agree with my point, that the
>> fossil record doesn't display a pattern of increasing complexity
>> during the Phanerozoic?
>
> What didn't you understand about "the increase in complexity does exist
> as an observable fact"?
I didn't understand what you meant by it. What do you mean by it? What
increase in complexity? Complexity of what, exactly?
>>>>>>> His explanation is the drunkard's walk, but he doesn't deny the
>>>>>>> observation of complexity increasing with time. So yes I want to
>>>>>>> defend that claim, and I want to see you attack that claim. I
>>>>>>> want you to show me mammals from before the K-T that are more
>>>>>>> complex than raccoons.
>>>>>>
>>>>>> No, if anything you need to show me mammals from before the K-T
>>>>>> that are less complex than raccoons.
>>>>>
>>>>> My knee-jerk reply was all of them. But after doing a small amount
>>>>> of checking, I don't know that I can defend that statement. One for
>>>>> you.
>>>>
>>>> Thanks. Is that a general acceptance of my point also regarding
>>>> turtles, cephalopods, etc.?
>>>
>>> Nope, sorry. After doing again a small amount of checking, it appears
>>> that complex cephalopods such as octopuses, and leatherback turtles
>>> (actually marine turtles in general) only appeared circa 120 million
>>> years ago. They may not be post K-T, but their predecessors do not
>>> exhibit their degree of complexity.
>>
>> What is your evidence that octopuses are more complex than previous
>> cephalopods, or that modern marine turtles are more complex than older
>> turtles?
>
> The octopuses are universally considered the most intelligent
> invertebrates.
How intelligent were ammonites? Do you know? How intelligent were any
shelless cephalopods that existed 500 million years ago? (We don't know
whether there were any, of course, because they don't fossilize.)
> Since marine turtles didn't exist before 120 million
> years ago, they have to be more complex than older marine turtles. There
> mere existence shows an increase in complexity among turtles, since they
> have successfully invaded a niche they did not previously occupy.
This is not actually true. Some of the oldest known turtles were marine;
Archelon, for example. And the increase in complexity you are talking
about here is apparently the complexity of an ecosystem or community
rather than of an organism.
> And while we're on that subject, all land animals and plants show an
> increase in complexity during the Phanerozoic, since there weren't any
> at the beginning of the Phanerozoic.
Again, you seem to be talking about ecological complexity, not
organismal complexity. Unless you want to claim that land animals are
universally more complex than aquatic animals.
Better to say that behavior has been genetically modified. It's not as
if some brand new gene encoding the behavior has just popped into
existence. Existing genes have been modified to alter some genetically
determined behavior. There is no reason to suppose that this makes the
organism more complex.
> Now
> traits may be lost, but the impact of the Baldwin effect is an increase
> in complexity. Unless you argue for an upper bound on complexity (and
> you have given no examples or argument for such an upper bound) so that
> a trait must be lost when one is gained, there is no reason for the
> Baldwin effect to do anything other than increase complexity. The trait
> loss is a separate effect that is random, while the Baldwin effect is
> directional.
I deny that assertion. It relies on a misunderstanding of genetic
mechanisms.
So what does that have to do with increasing complexity? And (to repeat
the question you ignored) why should modern Limulus being different from
ancient Limulus mean that they were also more complex?
>>>> Really, there is no chance of a general phenomenon here, based on
>>>> the history of life. If there were one, it would affect all groups,
>>>> and modern jellyfish, e.g., would be more complex than Paleozoic
>>>> jellyfish. Do you claim that to be the case?
>
> I didn't note this initially, but the claim that a general phenomenon
> would have to affect all groups is a non sequitur. There only has to be
> a general increase in complexity among most groups, with no
> countervailing decrease in complexity among the remaining groups. Are
> you claiming that the jellyfish have decreased in complexity?
No. And I agree. Not all groups have to increase in complexity for there
to be a general phenomenon, just most of them. Now I would contend that
very few groups have demonstrably increased in complexity since the
Cambrian. As examples of this I cite...everything. I will agree that
Chordata can be argued to have increased in general complexity. But what
else?
>>> Remember that there is a well documented increase in biodiversity
>>> with time.
>>
>> How is that relevant?
>
> Unless you want to state that the average complexity per species has
> decreased, an increase in number of species times the same average
> complexity per species equals an increase in overall complexity.
I deny that claim. Overall complexity cannot reasonably be computed by
adding up the complexities of individual organisms. 500 species of
Drosophila are not more complex than one species of Drosophila. And if
you measure complexity this way, it doesn't show up as an increase in
complexity of fossils.
>>> There is also an increase in symbiosis and sociality with time ( or
>>> are you going to argue that ants and naked mole rats were present in
>>> the early Phanerozoic).
>>
>> No. We don't actually know much about eusociality or lack thereof in
>> the Cambrian. There were certainly no ants, termites, or mammals; or
>> land life of any sort beyond bacteria, as far as I know. At any rate,
>> I'm sure that the right tail of the eusociality curve has extended
>> since the Cambrian. So?
>
> So there has been an increase in complexity.
If that's how you want to define it, I agree. But would you agree that
this is not a general increase in complexity, nor would it produce a
pattern in the fossil record?
>>> I can't say whether modern jellyfish are more complex than Paleozoic
>>> jellyfish ( although I would not be surprised if they were) - but
>>> there is still a trend towards increasing complexity.
>>
>> What trend? And what exactly do you mean when you say "trend"?
>>
> Well, let's see. There is an increase in skeletal complexity, there is
> an increase in individual behavioral complexity (intelligence), there is
> an increase in social behavioral complexity, there is an increase in
> ecosystem complexity (at least according to Ernest Major), there is an
> increase in species diversity, there is an increase in technological
> complexity (which we haven't previously discussed). Geez, I don't see
> any trend, do you?
No. What I see is an inability on your part to keep focused. If you want
to call right-tail phenomena increases, fine. But right-tail phenomena
don't produce patterns in the fossil record.
> I note that you still haven't given any counterargument to the
> prediction of increased complexity due to the better control added by
> additional feedback loops.
What prediction? What feedback loops? I don't remember any such
prediction, and I can't find one in this post.
Cj
>>
> Well, let's see. There is an increase in skeletal complexity, there is
> an increase in individual behavioral complexity (intelligence), there is
> an increase in social behavioral complexity, there is an increase in
> ecosystem complexity (at least according to Ernest Major), there is an
> increase in species diversity, there is an increase in technological
> complexity (which we haven't previously discussed). Geez, I don't see
> any trend, do you?
>
> Bill Morse
>
I don't think there are available data to demonstrate what you are
claiming. How do you discern the difference in behavioral complexity
between two species unless you have studied their behaviors? What do
you know about ecosystem complexity in the phanerozoic? Species
diversity? When, where and how?
William Morse
OK, now we are getting somewhere. I've got something to look up that
will hopefully educate me. And I did look it up. Interestingly, the
first hit on googling "terminal addition" is an article arguing for its
importance in the Cambrian. "Just isn't true?" In many cases derived
features _are_ a result of terminal addition. In other cases they are a
result of paedomorphosis. The latter is, of course, still an example of
adding a developmental step, although it may delete a later step.
>> So my statement is rather easy to justify. In fact the unwarranted
>> assumption is that an apomorphic feature would be less complex than
>> the plesiomorphic feature from which it develope. It is possible (in
>> theory one could find a route that skipped the primitive development)
>> but you would have to prove it. The assumption in the absence of more
>> detailed information is that the apomorphic feature is more complex.
>
> That may be your assumption. It's certainly not the assumption any
> modern biologist would make, and for good reason. Terminal addition is a
> false model of evolution.
The statement that "terminal addition is a false model of evolution " is
at best an obfuscation. Terminal addition is one mode of
evolution. And an added developmental step is required even in
paedomorphosis. The question is whether subsequent developmental steps
are deleted, and even if they are, is complexity reduced. The evidence
says otherwise (see below).
>>>> Admittedly, until we know a lot more about development it will not
>>>> be practical to compare the Kolmogorov complexity of say Drosophila
>>>> melanogaster and Acer rubrum.
>>>
>>> Or of any two species, as far as I can see. If you disagree, please
>>> compare the Kolmogorov complexities of Drosophila melanogaster and
>>> Drosophila simulans.
>>
>> Give me a detailed list of the differences between the two taxa, and I
>> will make the comparison.
>
> How exactly would you do that? But here you go:
>
> http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+melanogaster&db=0
>
>
> http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+simulans&db=0
Be careful what you wish for, right? I was actually looking for a
detailed list of phenotypical differences between the two taxa. You
didn't provide that. Admittedly, if I was actually good at measuring
Kolmogorov complexity, I should be able to use the cites to come up with
a comparison. Don't hold your breath :-)
>
> Of course most of the differences have no effect on phenotype, if that
> matters.
We could go into a whole other discussion of the significance of "junk"
DNA and "neutral" SNP's. but I don't want to go there.
If all other phyla had equal complexity, and Chordata had an increase in
complexity, that would mean there was an increase in complexity. So by
your math, I am right. Having already won the argument, I will say that
Chordata is not even arguable, its complexity _has_ increased during the
phanerozoic period. Following your suggestion, I looked at other phyla.
Arthropods - clear increase. Let's hear this from a developmental
biologist - Sean Carroll, in _Endless Forms Most Beautiful_, "The story
of arthropod evolution from the Cambrian onward is largely one of
increasing segment and limb type diversity." Molluscs - clear increase
(from _The Complete Encylopedia of the Animal World_, "Alike in their
fundamental morphology, molluscs have undergone a remarkable adaptive
radiation"). Brachiopods - increase followed by decrease. Annelids -not
as clear as chordates, arthropods, and molluscs, but they show an
increase in diversity if only because of the development of terrestrial
and freshwater forms. Coelenterates - it appears there was a
significant increase in complexity of corals in the Ordovician.
Echinoderms - increase followed by a decrease.
In sum, I really have no clue on what basis you are arguing for no
increase in complexity during the phanerozoic.
>>>> I did not make myself clear. My statement is that the increase in
>>>> complexity does exist as an observable fact. Gould I think might
>>>> have accepted this view:
>>>>
>>>> "And yet, undeniably (even for such curmudgeons as me), a basic fact
>>>> of the history of life - the basic fact, one might well say - seems
>>>> to cry out for progress as the central trend and defining feature of
>>>> life's history." (Full House, p. 145) Gould goes on to reject the
>>>> idea of a direction in evolution and offers the lengthening right
>>>> tail distribution as an alternative.
>>>
>>> This seems to me more like Darwin's rhetorical practice of making a
>>> claim only to refute it, though I don't have a copy of Full House
>>> handy to check. But if you're agreeing with Gould that any increase
>>> is a right-tail phenomenon, do you also agree with my point, that the
>>> fossil record doesn't display a pattern of increasing complexity
>>> during the Phanerozoic?
>>
>> What didn't you understand about "the increase in complexity does exist
>> as an observable fact"?
>
> I didn't understand what you meant by it. What do you mean by it? What
> increase in complexity? Complexity of what, exactly?
Complexity of life.
You have faith in intelligent ammonites because? It is of course
possible that there were intelligent shell-less cephalopods 500 million
years ago that disappeared without leaving any trace in the DNA record.
But why would one assume that without evidence? The mechanisms of
evolution tend to produce increased complexity, even if only as a
right-tail phenomenon.
>> Since marine turtles didn't exist before 120 million
>> years ago, they have to be more complex than older marine turtles.
>> There mere existence shows an increase in complexity among turtles,
>> since they have successfully invaded a niche they did not previously
>> occupy.
>
> This is not actually true. Some of the oldest known turtles were marine;
> Archelon, for example. And the increase in complexity you are talking
> about here is apparently the complexity of an ecosystem or community
> rather than of an organism.
>
>> And while we're on that subject, all land animals and plants show an
>> increase in complexity during the Phanerozoic, since there weren't any
>> at the beginning of the Phanerozoic.
>
> Again, you seem to be talking about ecological complexity, not
> organismal complexity. Unless you want to claim that land animals are
> universally more complex than aquatic animals.
Land animals, by definition, show an increase in complexity during the
phanerozoic, since they started at zero complexity. Unless you think
land animals are not animals, if land animals show an increase in
complexity and marine animals maintain equal complexity, then animals
show an increase in complexity during the phanerozoic. No one is arguing
that every single lineage increased in complexity, The question is
whether complexity has increased, and that has to be an overall measure.
Say what? The dominant mechanism of genetic change in evolution is
duplication followed by differentiation of one of the copies. This
mechanism is concordant with the evidence from the fossil record, that
a new trait is likely to involve an increase in complexity.
Because if you have to keep changing to avoid parasitism, then you will
increase in complexity if only as a right-tail phenomenon.
>>>>> Really, there is no chance of a general phenomenon here, based on
>>>>> the history of life. If there were one, it would affect all groups,
>>>>> and modern jellyfish, e.g., would be more complex than Paleozoic
>>>>> jellyfish. Do you claim that to be the case?
>>
>> I didn't note this initially, but the claim that a general phenomenon
>> would have to affect all groups is a non sequitur. There only has to
>> be a general increase in complexity among most groups, with no
>> countervailing decrease in complexity among the remaining groups. Are
>> you claiming that the jellyfish have decreased in complexity?
>
> No. And I agree. Not all groups have to increase in complexity for there
> to be a general phenomenon, just most of them. Now I would contend that
> very few groups have demonstrably increased in complexity since the
> Cambrian. As examples of this I cite...everything. I will agree that
> Chordata can be argued to have increased in general complexity. But what
> else?
As discussed above, the molluscs and the arthropods, and several others
if you want to insist on starting the clock at the beginning of the
Phanerozoic.
>>>> Remember that there is a well documented increase in biodiversity
>>>> with time.
>>>
>>> How is that relevant?
>>
>> Unless you want to state that the average complexity per species has
>> decreased, an increase in number of species times the same average
>> complexity per species equals an increase in overall complexity.
>
> I deny that claim. Overall complexity cannot reasonably be computed by
> adding up the complexities of individual organisms. 500 species of
> Drosophila are not more complex than one species of Drosophila. And if
> you measure complexity this way, it doesn't show up as an increase in
> complexity of fossils.
You can deny it, but how else are you going to compute overall complexity?
>>>> There is also an increase in symbiosis and sociality with time ( or
>>>> are you going to argue that ants and naked mole rats were present in
>>>> the early Phanerozoic).
>>>
>>> No. We don't actually know much about eusociality or lack thereof in
>>> the Cambrian. There were certainly no ants, termites, or mammals; or
>>> land life of any sort beyond bacteria, as far as I know. At any rate,
>>> I'm sure that the right tail of the eusociality curve has extended
>>> since the Cambrian. So?
>>
>> So there has been an increase in complexity.
>
> If that's how you want to define it, I agree. But would you agree that
> this is not a general increase in complexity, nor would it produce a
> pattern in the fossil record?
I think that it is a general increase in complexity, but agree that it
would be extraordinarily difficult to document in the fossil record.
>>>> I can't say whether modern jellyfish are more complex than Paleozoic
>>>> jellyfish ( although I would not be surprised if they were) - but
>>>> there is still a trend towards increasing complexity.
>>>
>>> What trend? And what exactly do you mean when you say "trend"?
>>>
>> Well, let's see. There is an increase in skeletal complexity, there is
>> an increase in individual behavioral complexity (intelligence), there is
>> an increase in social behavioral complexity, there is an increase in
>> ecosystem complexity (at least according to Ernest Major), there is an
>> increase in species diversity, there is an increase in technological
>> complexity (which we haven't previously discussed). Geez, I don't see
>> any trend, do you?
>
> No. What I see is an inability on your part to keep focused. If you want
> to call right-tail phenomena increases, fine. But right-tail phenomena
> don't produce patterns in the fossil record.
I am interrupted so often at work that I can no longer focus on anything
for longer than about fifteen minutes. Nevertheless, I fail to see any
basis for the statement that right-tail phenomena don't produce
patterns. Please explain.
>> I note that you still haven't given any counterargument to the
>> prediction of increased complexity due to the better control added by
>> additional feedback loops.
>
> What prediction? What feedback loops? I don't remember any such
> prediction, and I can't find one in this post.
>
What I said was that increased feedback loops provide more stability.
(The idea is not mine - I am just parroting Odum). Since feedback loops
increase complexity, and assuming stability is selected for (seems
obvious to me, but that doesn't make it so), selection should tend to
increase complexity.
Yours,
Bill Morse
John Harshman
No, paedomorphisis doesn't add a developmental step. It eliminates
steps, if anything, i.e it truncates development of some features. I
didn't mean to give the impression that terminal addition never happens.
It's just not the universal rule you were assuming.
>>> So my statement is rather easy to justify. In fact the unwarranted
>>> assumption is that an apomorphic feature would be less complex than
>>> the plesiomorphic feature from which it develope. It is possible (in
>>> theory one could find a route that skipped the primitive development)
>>> but you would have to prove it. The assumption in the absence of more
>>> detailed information is that the apomorphic feature is more complex.
>>
>> That may be your assumption. It's certainly not the assumption any
>> modern biologist would make, and for good reason. Terminal addition is
>> a false model of evolution.
>
> The statement that "terminal addition is a false model of evolution " is
> at best an obfuscation. Terminal addition is one mode of
> evolution. And an added developmental step is required even in
> paedomorphosis. The question is whether subsequent developmental steps
> are deleted, and even if they are, is complexity reduced. The evidence
> says otherwise (see below).
I await your justification.
>>>>> Admittedly, until we know a lot more about development it will not
>>>>> be practical to compare the Kolmogorov complexity of say
>>>>> Drosophila melanogaster and Acer rubrum.
>>>>
>>>> Or of any two species, as far as I can see. If you disagree, please
>>>> compare the Kolmogorov complexities of Drosophila melanogaster and
>>>> Drosophila simulans.
>>>
>>> Give me a detailed list of the differences between the two taxa, and
>>> I will make the comparison.
>>
>> How exactly would you do that? But here you go:
>>
>> http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+melanogaster&db=0
>>
>>
>> http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=108730966&clade=insect&org=D.+simulans&db=0
>
> Be careful what you wish for, right? I was actually looking for a
> detailed list of phenotypical differences between the two taxa. You
> didn't provide that. Admittedly, if I was actually good at measuring
> Kolmogorov complexity, I should be able to use the cites to come up with
> a comparison. Don't hold your breath :-)
You would have to be very, very good. What you would have would be the
complexities of the two genomes, which would not relate to the
complexities of the morphologies. Mind you, the morphologies would be in
there somwhere if you only knew how to read them.
>> Of course most of the differences have no effect on phenotype, if that
>> matters.
>
> We could go into a whole other discussion of the significance of "junk"
> DNA and "neutral" SNP's. but I don't want to go there.
You have weird opinions on that too?
Yes, but only within chordates. That would not make a general pattern in
the fossil record. I swear you are willing to forget what we're talking
about in order to win points in some game you're playing.
> So by
> your math, I am right. Having already won the argument, I will say that
> Chordata is not even arguable, its complexity _has_ increased during the
> phanerozoic period.
I think there are three major episodes of increase: first, an increase
in number of separate bony elements in gnathostomes; second, an increase
in cranial bone complexity in teleosts; third, and increease in
postcranial bone complexity in tetrapods. Then again, much else has
decreased; for example, cranial complexity has generally decreased in
tetrapods, and postcranial complexity has seriously decreased in frogs.
I think you'd have to work this out rigorously before you could really
make good a claim for a clear pattern of regular increase.
> Following your suggestion, I looked at other phyla.
> Arthropods - clear increase. Let's hear this from a developmental
> biologist - Sean Carroll, in _Endless Forms Most Beautiful_, "The story
> of arthropod evolution from the Cambrian onward is largely one of
> increasing segment and limb type diversity."
I'd like to hear Carroll's defense of this. There's plenty of segment
and limb type diversity in the Cambrian.
> Molluscs - clear increase
> (from _The Complete Encylopedia of the Animal World_, "Alike in their
> fundamental morphology, molluscs have undergone a remarkable adaptive
> radiation").
Adaptive radiation does not equal increase in the complexities of
individual organisms. You're quote mining at random here.
> Brachiopods - increase followed by decrease.
Increase of numbers of species and diversity. This does not translate to
complexity.
> Annelids -not
> as clear as chordates, arthropods, and molluscs, but they show an
> increase in diversity if only because of the development of terrestrial
> and freshwater forms. Coelenterates - it appears there was a
> significant increase in complexity of corals in the Ordovician.
> Echinoderms - increase followed by a decrease.
Nothing here either.
> In sum, I really have no clue on what basis you are arguing for no
> increase in complexity during the phanerozoic.
Fair enough. I have no clue on what basis you are arguing for an increase.
>>>>> I did not make myself clear. My statement is that the increase in
>>>>> complexity does exist as an observable fact. Gould I think might
>>>>> have accepted this view:
>>>>>
>>>>> "And yet, undeniably (even for such curmudgeons as me), a basic
>>>>> fact of the history of life - the basic fact, one might well say -
>>>>> seems to cry out for progress as the central trend and defining
>>>>> feature of life's history." (Full House, p. 145) Gould goes on to
>>>>> reject the idea of a direction in evolution and offers the
>>>>> lengthening right tail distribution as an alternative.
>>>>
>>>> This seems to me more like Darwin's rhetorical practice of making a
>>>> claim only to refute it, though I don't have a copy of Full House
>>>> handy to check. But if you're agreeing with Gould that any increase
>>>> is a right-tail phenomenon, do you also agree with my point, that
>>>> the fossil record doesn't display a pattern of increasing complexity
>>>> during the Phanerozoic?
>>>
>>> What didn't you understand about "the increase in complexity does exist
>>> as an observable fact"?
>>
>> I didn't understand what you meant by it. What do you mean by it? What
>> increase in complexity? Complexity of what, exactly?
>
> Complexity of life.
You understand that you have just communicated nothing, right? What did
you mean by "complexity of life"?
You understand that octopuses have approximately no fossil record,
right? And that we have no way of knowing how intelligent ammonites
were? Which DNA record?
>>> Since marine turtles didn't exist before 120 million
>>> years ago, they have to be more complex than older marine turtles.
>>> There mere existence shows an increase in complexity among turtles,
>>> since they have successfully invaded a niche they did not previously
>>> occupy.
>>
>> This is not actually true. Some of the oldest known turtles were
>> marine; Archelon, for example. And the increase in complexity you are
>> talking about here is apparently the complexity of an ecosystem or
>> community rather than of an organism.
>>
>>> And while we're on that subject, all land animals and plants show an
>>> increase in complexity during the Phanerozoic, since there weren't
>>> any at the beginning of the Phanerozoic.
>>
>> Again, you seem to be talking about ecological complexity, not
>> organismal complexity. Unless you want to claim that land animals are
>> universally more complex than aquatic animals.
>
> Land animals, by definition, show an increase in complexity during the
> phanerozoic, since they started at zero complexity. Unless you think
> land animals are not animals, if land animals show an increase in
> complexity and marine animals maintain equal complexity, then animals
> show an increase in complexity during the phanerozoic. No one is arguing
> that every single lineage increased in complexity, The question is
> whether complexity has increased, and that has to be an overall measure.
I'm sorry, but that's really stupid. Land animals didn't appear by
magic. You can compare the complexities of land animals to their aquatic
relatives. And again you seem to be talking about ecological complexity,
not morphological complexity.
Now here you're talking about genetic complexity, not morphological
complexity. And I also deny that duplication is the dominant mechanism,
through it's certainly common enough.
That was a serious non sequitur, and a non sequitur that didn't answer
my question either.
>>>>>> Really, there is no chance of a general phenomenon here, based on
>>>>>> the history of life. If there were one, it would affect all
>>>>>> groups, and modern jellyfish, e.g., would be more complex than
>>>>>> Paleozoic jellyfish. Do you claim that to be the case?
>>>
>>> I didn't note this initially, but the claim that a general phenomenon
>>> would have to affect all groups is a non sequitur. There only has to
>>> be a general increase in complexity among most groups, with no
>>> countervailing decrease in complexity among the remaining groups. Are
>>> you claiming that the jellyfish have decreased in complexity?
>>
>> No. And I agree. Not all groups have to increase in complexity for
>> there to be a general phenomenon, just most of them. Now I would
>> contend that very few groups have demonstrably increased in complexity
>> since the Cambrian. As examples of this I cite...everything. I will
>> agree that Chordata can be argued to have increased in general
>> complexity. But what else?
>
> As discussed above, the molluscs and the arthropods, and several others
> if you want to insist on starting the clock at the beginning of the
> Phanerozoic.
It's not my insistence. If you remember the point of this discussion,
it's about the Phanerozoic fossil record. And your claims are mostly not
related to morphological complexity of individuals.
>>>>> Remember that there is a well documented increase in biodiversity
>>>>> with time.
>>>>
>>>> How is that relevant?
>>>
>>> Unless you want to state that the average complexity per species has
>>> decreased, an increase in number of species times the same average
>>> complexity per species equals an increase in overall complexity.
>>
>> I deny that claim. Overall complexity cannot reasonably be computed by
>> adding up the complexities of individual organisms. 500 species of
>> Drosophila are not more complex than one species of Drosophila. And if
>> you measure complexity this way, it doesn't show up as an increase in
>> complexity of fossils.
>
> You can deny it, but how else are you going to compute overall complexity?
I would suggest using modal complexity. That has the advantage of not
conflating species numbers with organismal complexity.
>>>>> There is also an increase in symbiosis and sociality with time ( or
>>>>> are you going to argue that ants and naked mole rats were present
>>>>> in the early Phanerozoic).
>>>>
>>>> No. We don't actually know much about eusociality or lack thereof in
>>>> the Cambrian. There were certainly no ants, termites, or mammals; or
>>>> land life of any sort beyond bacteria, as far as I know. At any
>>>> rate, I'm sure that the right tail of the eusociality curve has
>>>> extended since the Cambrian. So?
>>>
>>> So there has been an increase in complexity.
>>
>> If that's how you want to define it, I agree. But would you agree that
>> this is not a general increase in complexity, nor would it produce a
>> pattern in the fossil record?
>
> I think that it is a general increase in complexity, but agree that it
> would be extraordinarily difficult to document in the fossil record.
Then we agree that this argument isn't about the point you initially
took issue with?
>>>>> I can't say whether modern jellyfish are more complex than
>>>>> Paleozoic jellyfish ( although I would not be surprised if they
>>>>> were) - but there is still a trend towards increasing complexity.
>>>>
>>>> What trend? And what exactly do you mean when you say "trend"?
>>>>
>>> Well, let's see. There is an increase in skeletal complexity, there is
>>> an increase in individual behavioral complexity (intelligence), there is
>>> an increase in social behavioral complexity, there is an increase in
>>> ecosystem complexity (at least according to Ernest Major), there is an
>>> increase in species diversity, there is an increase in technological
>>> complexity (which we haven't previously discussed). Geez, I don't see
>>> any trend, do you?
>>
>> No. What I see is an inability on your part to keep focused. If you
>> want to call right-tail phenomena increases, fine. But right-tail
>> phenomena don't produce patterns in the fossil record.
>
> I am interrupted so often at work that I can no longer focus on anything
> for longer than about fifteen minutes. Nevertheless, I fail to see any
> basis for the statement that right-tail phenomena don't produce
> patterns. Please explain.
Right-tail phenomena, by their very nature, are exceptions to the rule.
Go back and reread the original claim from "The Top 10 Myths about
Evolution".
>>> I note that you still haven't given any counterargument to the
>>> prediction of increased complexity due to the better control added by
>>> additional feedback loops.
>>
>> What prediction? What feedback loops? I don't remember any such
>> prediction, and I can't find one in this post.
>
> What I said was that increased feedback loops provide more stability.
> (The idea is not mine - I am just parroting Odum). Since feedback loops
> increase complexity, and assuming stability is selected for (seems
> obvious to me, but that doesn't make it so), selection should tend to
> increase complexity.
I can't respond to this, as I don't understand what you're saying here.
William Morse
The change involved in paedomorphosis is an elaboration of a
pre-existing developmental step, and adds complexity. In some cases
later steps are eliminated, reducing complexity, but this is not the
initial result.
And if I could do that I would be way too busy to have time to respond
to this thread.
>>> Of course most of the differences have no effect on phenotype, if
>>> that matters.
>>
>> We could go into a whole other discussion of the significance of "junk"
>> DNA and "neutral" SNP's. but I don't want to go there.
>
> You have weird opinions on that too?
My opinions on that may or may not be weird. The "too" is incorrect
since it is you who have weird opinions on the complexity issue. I've
already quoted Carroll and Gould. With just a quick check on my
bookshelf I found this from Matt Ridley in _Genome_ "The longer animals
existed, the more complex _some_ of them became. In particular, the
brains of the brainiest animals were bigger and bigger in each
successive age:" And this from E.O. Wilson in _Sociobiology_ "Four
groups occupy pinnacles high above the others: the colonial
invertebrates, the social insects, the nonhuman mammals, and man. Each
has basic qualities of social life unique to itself. Here, then, is the
paradox. Although the sequence just given proceeds from unquestionably
more primitive and older forms of life to more advanced and recent ones,
the key properties of social existence, including cohesiveness,
altruism, and cooperativeness, decline. It seems as though social
evolution has slowed as the body plan of the individual organism became
more elaborate." Note that neither of these books is at all about the
question, but both authors espouse an increase in complexity. I don't
have a copy of Dawkins' "The Blind Watchmaker" handy, but my
recollection is that I could readily find a similar statement in that
book.
Well, you agree that under a random walk model complexity
will increase, but you argue that there is no general pattern in the
fossil record. Now the original claim you objected to was only "When
asked to explain the existence of fossils and their unique layering,
many Young Earth Creationists say they're simply the remains of dead
creatures drowned in Noah's flood. But this doesn't explain why we find
the fossils of more complex animals higher in the rock strata." And
under both the random walk and the limited to Chordata increase, fossils
of more complex animals will be found higher in the rock strata.
>> So by
>> your math, I am right. Having already won the argument, I will say that
>> Chordata is not even arguable, its complexity _has_ increased during the
>> phanerozoic period.
>
> I think there are three major episodes of increase: first, an increase
> in number of separate bony elements in gnathostomes; second, an increase
> in cranial bone complexity in teleosts; third, and increease in
> postcranial bone complexity in tetrapods. Then again, much else has
> decreased; for example, cranial complexity has generally decreased in
> tetrapods, and postcranial complexity has seriously decreased in frogs.
> I think you'd have to work this out rigorously before you could really
> make good a claim for a clear pattern of regular increase.
My very first post on this thread conceded that the increase is not
monotonic. I have also hinted that if you moved your date of peak
morphologic complexity to a later date (e.g. the Jurassic) it would be
much more difficult for me to make my case. But to get down to cases:
yes the gnathostomes show a significant increase compared to the
ostracoderms. And there is also an increase in complexity shown in the
elasmobranches, with the addition of more tooth types and modifications
to the fins and tails in the hybodonts. This was followed by changes to
the notochord and myomeres and the appearance of an anal fin(involving
an increase in complexity) in the modern sharks.
Skipping ahead, your statement that postcranial complexity has decreased
in frogs, if I am reading your argument correctly, is based on
a reduction in the number of postcranial skeletal elements. However from
the standpoint of Kolmogorov complexity, simple repeats are relatively
easy, elaboration is hard. The labyrinthodonts had lots of repeats, but
that didn't make them more complex than frogs. But I may be misreading
you on this.
>> Following your suggestion, I looked at other phyla.
>> Arthropods - clear increase. Let's hear this from a developmental
>> biologist - Sean Carroll, in _Endless Forms Most Beautiful_, "The
>> story of arthropod evolution from the Cambrian onward is largely one
>> of increasing segment and limb type diversity."
>
> I'd like to hear Carroll's defense of this. There's plenty of segment
> and limb type diversity in the Cambrian.
But not as much as during subsequent periods. I will also quote from
_The Complete Encyclopedia of the Animal World_, "Evolution of the
arthropods has proceeded from long, thin animals with little
differentiation of the body, to much more compact creatures, the bodies
of which divided into progressivley more distring regions or tagmata. At
the same time, the number of legs becomes reduced, allowing greater
versatility" And why does Carroll have to "defend" the statement?
Everyone but you sees an increase in complexity since the Cambrian,
albeit not at the rate seen during the Cambrian.
>> Molluscs - clear increase (from _The Complete Encylopedia of the
>> Animal World_, "Alike in their fundamental morphology, molluscs have
>> undergone a remarkable adaptive radiation").
>
> Adaptive radiation does not equal increase in the complexities of
> individual organisms. You're quote mining at random here.
Ooh that's harsh :-). But no, I wasn't quote mining at random, I just
didn't want to go to the trouble of citing all the backup. I will just
cite this bit from the Canadian Encyclopedia website, " Gastropods
occupy more habitats and represent more species than any other molluscan
class. This extensive adaptive radiation was made possible through 3
major changes from the molluscan ancestral plan: development of a
complex head with elaborate receptors and nervous system; coiling of
shell; and torsion, involving a 180° twisting of the shell and visceral
mass over the lower body section."
>> Brachiopods - increase followed by decrease.
>
> Increase of numbers of species and diversity. This does not translate to
> complexity.
The reference was that the most derived taxa have disappeared, while the
primitive taxa remain.
>> Annelids -not as clear as chordates, arthropods, and molluscs, but
>> they show an increase in diversity if only because of the development
>> of terrestrial and freshwater forms. Coelenterates - it appears there
>> was a significant increase in complexity of corals in the Ordovician.
>> Echinoderms - increase followed by a decrease.
>
> Nothing here either.
An unsupported statement, without even the hint I gave of a discussion.
I have already said that my basis for complexity is Kolmogorov
complexity. When you find a good definition of life, let me know, but I
think apart from perhaps viruses if someone pointed to a specific
example we would both agree whether or not it was "life". Now you want
to limit the discussion to morphological complexity. Which is fine, but
I was only answering your question.
OK, some of that was frustration, not well thought out argument. But
some of that is nonsense on your part. We have fossil records of ancient
cephalopods, and they weren't shelless. Agreed that we can only infer
the DNA record based on DNA from surviving representatives of taxa, and
there aren't any surviving ammonites. But we can infer from the fossil
record and from our knowledge of development that the ammonites did not
possess any of the sophisticated sensory modes that appear to be a
prerequisite to intelligence.
>>>> Since marine turtles didn't exist before 120 million
>>>> years ago, they have to be more complex than older marine turtles.
>>>> There mere existence shows an increase in complexity among turtles,
>>>> since they have successfully invaded a niche they did not previously
>>>> occupy.
>>>
>>> This is not actually true. Some of the oldest known turtles were
>>> marine; Archelon, for example. And the increase in complexity you are
>>> talking about here is apparently the complexity of an ecosystem or
>>> community rather than of an organism.
>>>
>>>> And while we're on that subject, all land animals and plants show an
>>>> increase in complexity during the Phanerozoic, since there weren't
>>>> any at the beginning of the Phanerozoic.
>>>
>>> Again, you seem to be talking about ecological complexity, not
>>> organismal complexity. Unless you want to claim that land animals are
>>> universally more complex than aquatic animals.
But to revisit this, since you insisted I look at the original argument,
the statement you objected to as noted above was "When asked to
explain the existence of fossils and their unique layering, many Young
Earth Creationists say they're simply the remains of dead creatures
drowned in Noah's flood. But this doesn't explain why we find the
fossils of more complex animals higher in the rock strata." In the case
of land animals, complex ones will be higher in the rock strata simply
because there weren't any at the beginning of the Phanerozoic.
>> Land animals, by definition, show an increase in complexity during the
>> phanerozoic, since they started at zero complexity. Unless you think
>> land animals are not animals, if land animals show an increase in
>> complexity and marine animals maintain equal complexity, then animals
>> show an increase in complexity during the phanerozoic. No one is
>> arguing that every single lineage increased in complexity, The
>> question is whether complexity has increased, and that has to be an
>> overall measure.
>
> I'm sorry, but that's really stupid. Land animals didn't appear by
> magic. You can compare the complexities of land animals to their aquatic
> relatives. And again you seem to be talking about ecological complexity,
> not morphological complexity.
I'm sorry, but it is not my fault that you don't want to recognize the
general argument. Complexity has increased during the Phanerozoic along
a number of measures, including morphological development, species
diversity, ecological complexity, and behavioral repertoire. To many,
this would indicate an underlying cause, one that increases complexity.
But since you apparently believe that whatever cause was increasing
complexity prior to the Phanerozoic suddenly came to an end (God got
bored?), if I didn't know better I would guess you think that all of
these increases in complexity are simply due to magic.
(snip)
>>>> Now traits may be lost, but the impact of the Baldwin effect is an
>>>> increase in complexity. Unless you argue for an upper bound on
>>>> complexity (and you have given no examples or argument for such an
>>>> upper bound) so that a trait must be lost when one is gained, there
>>>> is no reason for the Baldwin effect to do anything other than
>>>> increase complexity. The trait loss is a separate effect that is
>>>> random, while the Baldwin effect is directional.
>>>
>>> I deny that assertion. It relies on a misunderstanding of genetic
>>> mechanisms.
>>
>> Say what? The dominant mechanism of genetic change in evolution is
>> duplication followed by differentiation of one of the copies. This
>> mechanism is concordant with the evidence from the fossil record,
>> that a new trait is likely to involve an increase in complexity.
>
> Now here you're talking about genetic complexity, not morphological
> complexity. And I also deny that duplication is the dominant mechanism,
> through it's certainly common enough.
And common enough is all that is needed for my assertion about trait
loss vs. Baldwin effect to be correct, unless you want to provide a
better argument. So how does my assertion "rely on a misunderstanding of
genetic mechanism" ?
(snip)
Wrong, it both exactly followed, and it answered your question. But I
will try to clarify: sex is maintained because if you don't continually
change, you will fall prey to parasites.If the change is only random,
then it can move in the direction of lower complexity or greater
complexity. Since there is a limit on lower complexity, it will on
average move in the direction of greater complexity.
>>>>>>> Really, there is no chance of a general phenomenon here, based on
>>>>>>> the history of life. If there were one, it would affect all
>>>>>>> groups, and modern jellyfish, e.g., would be more complex than
>>>>>>> Paleozoic jellyfish. Do you claim that to be the case?
>>>>
>>>> I didn't note this initially, but the claim that a general
>>>> phenomenon would have to affect all groups is a non sequitur. There
>>>> only has to be a general increase in complexity among most groups,
>>>> with no countervailing decrease in complexity among the remaining
>>>> groups. Are you claiming that the jellyfish have decreased in
>>>> complexity?
>>>
>>> No. And I agree. Not all groups have to increase in complexity for
>>> there to be a general phenomenon, just most of them. Now I would
>>> contend that very few groups have demonstrably increased in
>>> complexity since the Cambrian. As examples of this I
>>> cite...everything. I will agree that Chordata can be argued to have
>>> increased in general complexity. But what else?
>>
>> As discussed above, the molluscs and the arthropods, and several
>> others if you want to insist on starting the clock at the beginning of
>> the Phanerozoic.
>
> It's not my insistence. If you remember the point of this discussion,
> it's about the Phanerozoic fossil record. And your claims are mostly not
> related to morphological complexity of individuals.
True enough. I was trying to introduce a general argument. But since you
don't want to consider the general argument, I have provided specific
arguments.
We agree that you are unwilling to generalize the argument, not that my
argument isn't about the point ;-)
>>>>>> I can't say whether modern jellyfish are more complex than
>>>>>> Paleozoic jellyfish ( although I would not be surprised if they
>>>>>> were) - but there is still a trend towards increasing complexity.
>>>>>
>>>>> What trend? And what exactly do you mean when you say "trend"?
>>>>>
>>>> Well, let's see. There is an increase in skeletal complexity, there is
>>>> an increase in individual behavioral complexity (intelligence),
>>>> there is
>>>> an increase in social behavioral complexity, there is an increase in
>>>> ecosystem complexity (at least according to Ernest Major), there is an
>>>> increase in species diversity, there is an increase in technological
>>>> complexity (which we haven't previously discussed). Geez, I don't
>>>> see any trend, do you?
>>>
>>> No. What I see is an inability on your part to keep focused. If you
>>> want to call right-tail phenomena increases, fine. But right-tail
>>> phenomena don't produce patterns in the fossil record.
>>
>> I am interrupted so often at work that I can no longer focus on
>> anything for longer than about fifteen minutes. Nevertheless, I fail
>> to see any basis for the statement that right-tail phenomena don't
>> produce patterns. Please explain.
>
> Right-tail phenomena, by their very nature, are exceptions to the rule.
I disagree. Right-tail phenomena are expected by the rule, not
exceptions to the rule. And the phenomenon we are talking about is that
we _expect to see_ more right-tail examples solely because of the left
wall. So we should expect to see patterns of increasing complexity in
the fossil record, unless you think the fossil record has some bias that
makes it a non-representative sample.
> Go back and reread the original claim from "The Top 10 Myths about
> Evolution".
I have, as noted above.
>>>> I note that you still haven't given any counterargument to the
>>>> prediction of increased complexity due to the better control added
>>>> by additional feedback loops.
>>>
>>> What prediction? What feedback loops? I don't remember any such
>>> prediction, and I can't find one in this post.
>>
>> What I said was that increased feedback loops provide more stability.
>> (The idea is not mine - I am just parroting Odum). Since feedback
>> loops increase complexity, and assuming stability is selected for
>> (seems obvious to me, but that doesn't make it so), selection should
>> tend to increase complexity.
>
> I can't respond to this, as I don't understand what you're saying here.
>
Sucks to be you :-) Seriously, I would try to do a better job of
explaining but this is already way too long. Maybe another time, as the
discussion seems to come reasonably often on the newsgroup. The
Odum reference is to _Environment, Power, and Society_, still worth
reading even though now quite dated.
Yours at length,
Bill Morse
John Harshman
Where do you get this notion? Paedomorphosis involves either the slowing
down of development of most adult traits, or a speeding up of
development of the adult reproductive system. It doesn't add anything
that wasn't there before, just alters the timing of events.
Right. So how can you make the assertions you did?
>>>> Of course most of the differences have no effect on phenotype, if
>>>> that matters.
>>>
>>> We could go into a whole other discussion of the significance of "junk"
>>> DNA and "neutral" SNP's. but I don't want to go there.
>>
>> You have weird opinions on that too?
>
> My opinions on that may or may not be weird. The "too" is incorrect
> since it is you who have weird opinions on the complexity issue. I've
> already quoted Carroll and Gould.
Though not to much effect. The Gould quote is actually against your thesis.
> With just a quick check on my
> bookshelf I found this from Matt Ridley in _Genome_ "The longer animals
> existed, the more complex _some_ of them became. In particular, the
> brains of the brainiest animals were bigger and bigger in each
> successive age:"
True, but again another right tail phenomenon.
> And this from E.O. Wilson in _Sociobiology_ "Four
> groups occupy pinnacles high above the others: the colonial
> invertebrates, the social insects, the nonhuman mammals, and man. Each
> has basic qualities of social life unique to itself. Here, then, is the
> paradox. Although the sequence just given proceeds from unquestionably
> more primitive and older forms of life to more advanced and recent ones,
> the key properties of social existence, including cohesiveness,
> altruism, and cooperativeness, decline. It seems as though social
> evolution has slowed as the body plan of the individual organism became
> more elaborate."
Note that "more advanced" doesn't mean "better" or even "more
complicated". Your entire point seems to lie in the words "became more
elaborate". But in fact I don't think either you or Wilson could back
that up. It's poor form to quote a throwaway line as if it represents
Wilson's considered opinion.
> Note that neither of these books is at all about the
> question, but both authors espouse an increase in complexity. I don't
> have a copy of Dawkins' "The Blind Watchmaker" handy, but my
> recollection is that I could readily find a similar statement in that
> book.
I doubt it. But feel free to try. Quote-mining will get you as far as it
gets creationists.
No. I agree that the complexity of the most complex organism will tend
to increase, but I consider that quite different from "complexity will
increase".
> but you argue that there is no general pattern in the
> fossil record. Now the original claim you objected to was only "When
> asked to explain the existence of fossils and their unique layering,
> many Young Earth Creationists say they're simply the remains of dead
> creatures drowned in Noah's flood. But this doesn't explain why we find
> the fossils of more complex animals higher in the rock strata." And
> under both the random walk and the limited to Chordata increase, fossils
> of more complex animals will be found higher in the rock strata.
No they won't. If you happen to find only the most complex animal
existing at any given time, you will see a pattern. But how likely is that?
>>> So by
>>> your math, I am right. Having already won the argument, I will say that
>>> Chordata is not even arguable, its complexity _has_ increased during the
>>> phanerozoic period.
>>
>> I think there are three major episodes of increase: first, an increase
>> in number of separate bony elements in gnathostomes; second, an
>> increase in cranial bone complexity in teleosts; third, and increease
>> in postcranial bone complexity in tetrapods. Then again, much else has
>> decreased; for example, cranial complexity has generally decreased in
>> tetrapods, and postcranial complexity has seriously decreased in
>> frogs. I think you'd have to work this out rigorously before you could
>> really make good a claim for a clear pattern of regular increase.
>
> My very first post on this thread conceded that the increase is not
> monotonic. I have also hinted that if you moved your date of peak
> morphologic complexity to a later date (e.g. the Jurassic) it would be
> much more difficult for me to make my case.
What date of peak morphological complexity?
> But to get down to cases:
> yes the gnathostomes show a significant increase compared to the
> ostracoderms. And there is also an increase in complexity shown in the
> elasmobranches, with the addition of more tooth types and modifications
> to the fins and tails in the hybodonts.
This is again an increase in ecological variation, not an increase in
complexity of individuals. A given shark will typically have one tooth type.
> This was followed by changes to
> the notochord and myomeres and the appearance of an anal fin(involving
> an increase in complexity) in the modern sharks.
I don't see any increase in complexity there either. And early sharks
had an anal fin.
> Skipping ahead, your statement that postcranial complexity has decreased
> in frogs, if I am reading your argument correctly, is based on
> a reduction in the number of postcranial skeletal elements. However from
> the standpoint of Kolmogorov complexity, simple repeats are relatively
> easy, elaboration is hard. The labyrinthodonts had lots of repeats, but
> that didn't make them more complex than frogs. But I may be misreading
> you on this.
It seems to me that if you replace a dozen elements with one, that's a
reduction in complexity. You can't claim that the one element is "more
differentiated" than the dozen; one element can't be differentiated.
>>> Following your suggestion, I looked at other phyla.
>>> Arthropods - clear increase. Let's hear this from a developmental
>>> biologist - Sean Carroll, in _Endless Forms Most Beautiful_, "The
>>> story of arthropod evolution from the Cambrian onward is largely one
>>> of increasing segment and limb type diversity."
>>
>> I'd like to hear Carroll's defense of this. There's plenty of segment
>> and limb type diversity in the Cambrian.
>
> But not as much as during subsequent periods.
Let's see that backed up with something.
> I will also quote from
> _The Complete Encyclopedia of the Animal World_, "Evolution of the
> arthropods has proceeded from long, thin animals with little
> differentiation of the body, to much more compact creatures, the bodies
> of which divided into progressivley more distring regions or tagmata. At
> the same time, the number of legs becomes reduced, allowing greater
> versatility" And why does Carroll have to "defend" the statement?
> Everyone but you sees an increase in complexity since the Cambrian,
> albeit not at the rate seen during the Cambrian.
There's plenty of tagmosis during the Cambrian. If this claim is so
obvious, it should be easy to show evidence for it. One somewhat related
study I think of (by Richard Fortey, I think) found that Cambrian and
Recent arthropods occupy about the same amount of morphospace. Not the
same thing as individual complexity, but as close as I can get from memory.
>>> Molluscs - clear increase (from _The Complete Encylopedia of the
>>> Animal World_, "Alike in their fundamental morphology, molluscs have
>>> undergone a remarkable adaptive radiation").
>>
>> Adaptive radiation does not equal increase in the complexities of
>> individual organisms. You're quote mining at random here.
>
> Ooh that's harsh :-). But no, I wasn't quote mining at random, I just
> didn't want to go to the trouble of citing all the backup. I will just
> cite this bit from the Canadian Encyclopedia website, " Gastropods
> occupy more habitats and represent more species than any other molluscan
> class. This extensive adaptive radiation was made possible through 3
> major changes from the molluscan ancestral plan: development of a
> complex head with elaborate receptors and nervous system; coiling of
> shell; and torsion, involving a 180° twisting of the shell and visceral
> mass over the lower body section."
All these happened in the Cambrian, as far as I know, though the complex
head wouldn't show up in fossils.
>>> Brachiopods - increase followed by decrease.
>>
>> Increase of numbers of species and diversity. This does not translate
>> to complexity.
>
> The reference was that the most derived taxa have disappeared, while the
> primitive taxa remain.
Derived doesn't mean more complex. It just means appearing later in an
evolutionary sequence.
>>> Annelids -not as clear as chordates, arthropods, and molluscs, but
>>> they show an increase in diversity if only because of the development
>>> of terrestrial and freshwater forms. Coelenterates - it appears
>>> there was a significant increase in complexity of corals in the
>>> Ordovician. Echinoderms - increase followed by a decrease.
>>
>> Nothing here either.
>
> An unsupported statement, without even the hint I gave of a discussion.
Again, increase in diversity doesn't mean increase in complexity. I
don't know about the corals; perhaps you could elaborate. For the
echinoderms, you don't even say what increased and decreased.
You keep diving into things like diversity and ecological complexity, so
the question is "Kolmogorov complexity of what aspect of life?" From
what I can tell, it changes from moment to moment.
Obviously, since what is preserved is the shell. That's why shell-less
cephalopods don't have a fossil record. No shells to be preserved. Based
on DNA, modern shell-less cephalopods date back (if I recall) into the
Mesozoic. Of extinct shell-less groups, we know nothing. But that
doesn't mean there weren't any. The fossil record of cnidarians, for
example, is almost entirely the fossil record of corals. But "coral"
just means any cnidarian that develops a lime skeleton. "Coral" isn't a
group, and we know almost nothing about relationships between octacorals
and hexacorals, much less tabulates. Except that there's a lot of
unskeletonized cnidarians in their ancestry.
Taphonomic bias isn't something you can jsut ignore.
> Agreed that we can only infer
> the DNA record based on DNA from surviving representatives of taxa, and
> there aren't any surviving ammonites. But we can infer from the fossil
> record and from our knowledge of development that the ammonites did not
> possess any of the sophisticated sensory modes that appear to be a
> prerequisite to intelligence.
We can? How can we do this?
>>>>> Since marine turtles didn't exist before 120 million
>>>>> years ago, they have to be more complex than older marine turtles.
>>>>> There mere existence shows an increase in complexity among turtles,
>>>>> since they have successfully invaded a niche they did not
>>>>> previously occupy.
>>>>
>>>> This is not actually true. Some of the oldest known turtles were
>>>> marine; Archelon, for example. And the increase in complexity you
>>>> are talking about here is apparently the complexity of an ecosystem
>>>> or community rather than of an organism.
>>>>
>>>>> And while we're on that subject, all land animals and plants show an
>>>>> increase in complexity during the Phanerozoic, since there weren't
>>>>> any at the beginning of the Phanerozoic.
>>>>
>>>> Again, you seem to be talking about ecological complexity, not
>>>> organismal complexity. Unless you want to claim that land animals
>>>> are universally more complex than aquatic animals.
>
> But to revisit this, since you insisted I look at the original argument,
> the statement you objected to as noted above was "When asked to
> explain the existence of fossils and their unique layering, many Young
> Earth Creationists say they're simply the remains of dead creatures
> drowned in Noah's flood. But this doesn't explain why we find the
> fossils of more complex animals higher in the rock strata." In the case
> of land animals, complex ones will be higher in the rock strata simply
> because there weren't any at the beginning of the Phanerozoic.
This is playing with words. You could say this about any group. Cenozoic
horses are more complex than Mesozoic horses. Recent foxes are more
complex than Oligocene foxes. Cretaceous forams are more complex than
Permian forams. But to say that is to say nothing.
>>> Land animals, by definition, show an increase in complexity during
>>> the phanerozoic, since they started at zero complexity. Unless you
>>> think land animals are not animals, if land animals show an increase
>>> in complexity and marine animals maintain equal complexity, then
>>> animals show an increase in complexity during the phanerozoic. No one
>>> is arguing that every single lineage increased in complexity, The
>>> question is whether complexity has increased, and that has to be an
>>> overall measure.
>>
>> I'm sorry, but that's really stupid. Land animals didn't appear by
>> magic. You can compare the complexities of land animals to their
>> aquatic relatives. And again you seem to be talking about ecological
>> complexity, not morphological complexity.
>
> I'm sorry, but it is not my fault that you don't want to recognize the
> general argument. Complexity has increased during the Phanerozoic along
> a number of measures, including morphological development, species
> diversity, ecological complexity, and behavioral repertoire. To many,
> this would indicate an underlying cause, one that increases complexity.
> But since you apparently believe that whatever cause was increasing
> complexity prior to the Phanerozoic suddenly came to an end (God got
> bored?), if I didn't know better I would guess you think that all of
> these increases in complexity are simply due to magic.
None of these would create a pattern in the fossil record except
"morphological development", if I get what you mean by that.
>>>>> Now traits may be lost, but the impact of the Baldwin effect is an
>>>>> increase in complexity. Unless you argue for an upper bound on
>>>>> complexity (and you have given no examples or argument for such an
>>>>> upper bound) so that a trait must be lost when one is gained, there
>>>>> is no reason for the Baldwin effect to do anything other than
>>>>> increase complexity. The trait loss is a separate effect that is
>>>>> random, while the Baldwin effect is directional.
>>>>
>>>> I deny that assertion. It relies on a misunderstanding of genetic
>>>> mechanisms.
>>>
>>> Say what? The dominant mechanism of genetic change in evolution is
>>> duplication followed by differentiation of one of the copies. This
>>> mechanism is concordant with the evidence from the fossil record,
>>> that a new trait is likely to involve an increase in complexity.
>>
>> Now here you're talking about genetic complexity, not morphological
>> complexity. And I also deny that duplication is the dominant
>> mechanism, through it's certainly common enough.
>
> And common enough is all that is needed for my assertion about trait
> loss vs. Baldwin effect to be correct, unless you want to provide a
> better argument. So how does my assertion "rely on a misunderstanding of
> genetic mechanism" ?
I really don't see your argument here.
Only if you start near the limit. Sexual organisms are all far from the
limit.
Hey, you're the one taking issue with my original claim. If you want to
start a new topic, say so. What you can't do is start a new topic and
say it's addressing my original claim.
!?
I do. The Phanerozoic fossil record in fact doesn't begin anywhere near
the left wall, and so there is no expected bias toward increasing
complexity of the mean, much less the mode.
>> Go back and reread the original claim from "The Top 10 Myths about
>> Evolution".
>
> I have, as noted above.
>
>
>>>>> I note that you still haven't given any counterargument to the
>>>>> prediction of increased complexity due to the better control added
>>>>> by additional feedback loops.
>>>>
>>>> What prediction? What feedback loops? I don't remember any such
>>>> prediction, and I can't find one in this post.
>>>
>>> What I said was that increased feedback loops provide more stability.
>>> (The idea is not mine - I am just parroting Odum). Since feedback
>>> loops increase complexity, and assuming stability is selected for
>>> (seems obvious to me, but that doesn't make it so), selection should
>>> tend to increase complexity.
>>
>> I can't respond to this, as I don't understand what you're saying here.
>>
> Sucks to be you :-) Seriously, I would try to do a better job of
> explaining but this is already way too long. Maybe another time, as the
> discussion seems to come reasonably often on the newsgroup. The Odum
> reference is to _Environment, Power, and Society_, still worth reading
> even though now quite dated.
I don't even know who this Odum person is, I'm sorry to say.
William Morse
Sorry to take so long replying. With regard to social behavior
complexity, coral reefs and termite mounds do appear in the fossil
record. I was just quoting Ernest Major on ecosystem complexity,
although increased species diversity would argue for increased ecosystem
complexity just because it implies additional niches. As to species
diversity, google Phanerozoic and look at the Wikipedia article that
comes up on top. For behavioral complexity one has to make the
assumption that surviving representatives of various taxa have a similar
behavioral repertoire as their fossil antecedents. Comparing these with
surviving representatives of more recently derived taxa, one sees an
increase in complexity of behavior.
Yours,
Bill Morse
William Morse
(snip)
> I don't even know who this Odum person is, I'm sorry to say.
Ha! Ha! Good one, John. You actually had me believing this whole thread
that you were seriously arguing complexity hadn't increased since the
Cambrian. I can't believe I bought into it. I wondered a little bit
earlier if you weren't pulling my leg, since you were disagreeing with
all of the top science writers in the field. But then you claimed not to
know who Odum was. Such a kidder. I can't believe you kept a straight
face for so long!
Yours,
Bill Morse
John Harshman
I will freely admit that ecology is not my field, and my one ecology
course was a very long time ago. So I suppose this means you're going to
declare victory, take your toys, and go home?
William Morse
I have tried appealing to authority, and you accuse me of quote mining.
I have tried appealing to evidence - including references(I haven't
cited a lot of it, as I am not a paleontologist and it takes a fair
amount of work for me to come up with examples), and you say I am
incorrect (without citing references) or that these are "right tail
phenomena" (which is what Gould says in _Full House_) and that they
therefore won't appear in the fossil record (which contradicts what
Gould says in _Full House_).
I have tried appealing to coherence - that the same factors that
produced the increase in complexity prior to the Phanerozoic haven't
changed, that we have well documented genetic mechanisms (e.g.
duplication) and well documented developmental mechanisms (e.g. terminal
addition) that tend to add complexity, that we have reason to believe
from more fundamental mechanisms that an increase in complexity is
likely in systems that rely on feedback loops - and you say I am getting
away from the point.
Forgive me for thinking that you aren't taking this argument seriously.
So yes I am going to pick up my toys, since I have been unable to
convince you and I am tired of getting dissed when I try. Your
arguments have similarly failed to convince me. Victory don't enter the
picture, does it?
And I am already at home :-)
Yours,
Bill Morse
John Harshman
> John Harshman wrote:
>> William Morse wrote:
>>> John Harshman wrote:
>>>
>>> (snip)
>>>> I don't even know who this Odum person is, I'm sorry to say.
>>>
>>>
>>> Ha! Ha! Good one, John. You actually had me believing this whole
>>> thread that you were seriously arguing complexity hadn't increased
>>> since the Cambrian. I can't believe I bought into it. I wondered a
>>> little bit earlier if you weren't pulling my leg, since you were
>>> disagreeing with all of the top science writers in the field. But
>>> then you claimed not to know who Odum was. Such a kidder. I can't
>>> believe you kept a straight face for so long!
>>
>> I will freely admit that ecology is not my field, and my one ecology
>> course was a very long time ago. So I suppose this means you're going
>> to declare victory, take your toys, and go home?
>
> I have tried appealing to authority, and you accuse me of quote mining.
Never liked appeals to authority, and as for quote mining, I believe you
have misinterpreted at least some of those quotes.
> I have tried appealing to evidence - including references(I haven't
> cited a lot of it, as I am not a paleontologist and it takes a fair
> amount of work for me to come up with examples), and you say I am
> incorrect (without citing references) or that these are "right tail
> phenomena" (which is what Gould says in _Full House_) and that they
> therefore won't appear in the fossil record (which contradicts what
> Gould says in _Full House_).
I never said it didn't appear. What I said is that it wouldn't make for
a pattern of appearances in the fossil record as described in the
original post.
> I have tried appealing to coherence - that the same factors that
> produced the increase in complexity prior to the Phanerozoic haven't
> changed, that we have well documented genetic mechanisms (e.g.
> duplication) and well documented developmental mechanisms (e.g. terminal
> addition) that tend to add complexity, that we have reason to believe
> from more fundamental mechanisms that an increase in complexity is
> likely in systems that rely on feedback loops - and you say I am getting
> away from the point.
Indeed you are, since none of this has to do with a pattern in the
fossil record. It might conceivably explain such a pattern, if indeed
there was one.
> Forgive me for thinking that you aren't taking this argument seriously.
I forgive you. I'm a forgiving sort.
> So yes I am going to pick up my toys, since I have been unable to
> convince you and I am tired of getting dissed when I try. Your
> arguments have similarly failed to convince me. Victory don't enter the
> picture, does it?
Then why do I get the impression that you're always scoring points
rather than just making points?
> And I am already at home :-)
So you don't have far to move your toys.