Pursuing paramorphies.
Elaine Morgan
Consider this cluster of autapomorphies.
The whiteness of the polar bear is unique among bears i.e. it is an
autapomorphy. So is the whiteness or seasonal whiteness of the ermine
among mustelids, the arctic fox among
canids, the arctic hare among lagomorphs. There is clearly some kind of
pattern there that is trying to tell us something. (in this case
something glaringly obvious).
But if you are a systematist and focus your attention on construction
cladograms, there is no way you can represent that pattern. In your
diagrams it disappears from view.
You have words for genetical resemblances - plesiomorphic,
symplesiomorphic - but no word for the striking resembance between the
coats of those unrelated mammals. I suggest "paramorphic". It may be
objected that I am talking about the old familiar cocept of convergent
evolution, but that phrase does not readily adapt into an adjective,
and besides the systematists seem more at home with, or more impressed
by, Greek roots than Latin ones. (I think paramorphic means something
in physics, but that will not lead to any confusion. Anyway
plesiomorph was already a word before the cladists borrowed it)
If I ask why I so closely resemble a chimpanzee (as we all do ) the
systematists can go a long way towards answering me by constructing a
family tree. If I ask why I am nevertheless so different from a
chimpanzee (as we all are) they are dumb. They are not interested in
anything that happened to my ancestors since the last common
ancestor. They only glance at the autapomorphies long enough to ensure
themselves they can be safely shuffled out of the way and forgotten
about.
But the second question is the one I wish to address. I might borrow
the current technical term for this frame of mind, and say I do not
care a flying rat's ass why I resemble a chimpanzee; I want to know why
I am different. And I suggest that anyone asking that question and
following the advice to mug up on systematics will find that they are
reading *The Wrong Books.*
Systematics only tells you about your pedigree up to the l.c.a.
Paramorphics throws light on what happened to your species since that
time, and may throw light on the cause of speciation. For instance, in
the cases quoted in the first paragraph, the paramorphy tells you that
all these species moved north. If you told a biologist"I have
discovered a new species of lemmings, and they are white", you would
not have to disclose where they came from. The biologist would be ready
to give odds of twenty to one that they came from the arctic. To
discover the reason for our own unusally rich collection of
autapomorphies, the most promising method is to seek for
paramorphic developments in other unrelated species.
So while I wish you every success, David Froehlich, in your chosen
branch of science, I hope you will like a good American grant me
the inalienable right to life, liberty, and the pursuit of
paramorphies
Apology.
I am sorry, the sentence you complained of was indeed very convoluted
and I am ashamed of it. What I was trying to say was this. A human
fetus recapitulates some of the earlier stages of our
evolutionary journey e.g. at one time it has a tail, at one time its
face and body are covered with hair. But it takes some time for new
developments to be incorporated into the prenatal repertoire.
I could not immediately think of any post-afarensis development that
had been so incorporated. For example, one late development was the
change in the inter-membral index that resulted in our legs being much
longer than our arms , and that certainly does not begin to happen
before birth.
Somebody - sorry, I forget who - challenged this and said there were
many late developments that were incorporated in the fetus, but cited
only one: relative brain growth.
That example will not work. Our babies do not have much bigger brain
size relative to body size than chimpanzees. The relative cranial
capacity of a new born human is 9.9 % of its body size. The relatice
cranial capacity of a chimp is 9.7% of its body size. That is a fairly
small difference, and Robin Martin showed that relative brain growth
had already begun in A. Afarensis.
I would guess that the unborn human begins shedding its body hair at
around the same stage of gestation that the unborn chimp begins to
develop knuckle pads; and that this suggests we have been naked about
as long as the apes have been knuckle-walkers. I cannot prove this . It
is a speculation. But the first half of it at least is testable.
Elaine.
David J. Froehlich
>
>
>Consider this cluster of autapomorphies.
>
>The whiteness of the polar bear is unique among bears i.e. it is an
>autapomorphy. So is the whiteness or seasonal whiteness of the ermine
>among mustelids, the arctic fox among
>canids, the arctic hare among lagomorphs. There is clearly some kind of
>pattern there that is trying to tell us something. (in this case
>something glaringly obvious).
But is a white coat necessarily an arctic feature? Could it not also
evolve at high altitude? Wouldn't these two features be
indistinguishable? Did other features that you find in these organisms
evolve at the same time? Is it possible to actually determine whether
these characters evolved at the same time? Are all arctic animals
white? If an animal is white is it arctic? If not, is it not arctic?
Could it be that the similarity is more complex than you propose?
>But if you are a systematist and focus your attention on construction
>cladograms, there is no way you can represent that pattern. In your
>diagrams it disappears from view.
It doesn't disapear, to explain it however requires the cladogram and
the autapomorphies.
>You have words for genetical resemblances - plesiomorphic,
>symplesiomorphic - but no word for the striking resembance between the
>coats of those unrelated mammals. I suggest "paramorphic". It may be
>objected that I am talking about the old familiar cocept of convergent
>evolution, but that phrase does not readily adapt into an adjective,
>and besides the systematists seem more at home with, or more impressed
>by, Greek roots than Latin ones. (I think paramorphic means something
>in physics, but that will not lead to any confusion. Anyway
>plesiomorph was already a word before the cladists borrowed it)
Gack!!! It will definately lead to confusion, there is a concept in
ontogeny called paramorphosis (entirely to close). Also, there is a
word in clado-babble. It is homoplasy (similarity not due to shared
evolutionary history).
>If I ask why I so closely resemble a chimpanzee (as we all do ) the
>systematists can go a long way towards answering me by constructing a
>family tree. If I ask why I am nevertheless so different from a
>chimpanzee (as we all are) they are dumb. They are not interested in
>anything that happened to my ancestors since the last common
>ancestor. They only glance at the autapomorphies long enough to ensure
>themselves they can be safely shuffled out of the way and forgotten
>about.
Who is forgetting them? All I am advocating is that they be dealt with
in the frame of reference appropriate (the phylogenetic system) and that
they be dealt with is a testable way. You continually take multiple
autapomorphies and place them together on the tree without any evidence
for that association. You find it convinient because you can point to
all the features as "aquatic". Yet I have seen no evidence to support
these similarities as shared, or even associated other than they occur
in modern humans. You look at fat distirbution, hairlessness, and
numerous other features and say "wow, they all must be aquatic" and what
I want you to do is look at all the features and provide me with evidence
for why they must be associated with each other and not independently
aquired. If you cannot link them, then why should we assume (and it is
an assumption, do not kid yourself) that they all are associated with the
same evolutionary event. If you assume they all appeared at the same
time then you cannot test that assumption (and in effect, you have
assumed the very hypothesis you want to test (AAH).
>But the second question is the one I wish to address. I might borrow
>the current technical term for this frame of mind, and say I do not
>care a flying rat's ass why I resemble a chimpanzee; I want to know why
>I am different. And I suggest that anyone asking that question and
>following the advice to mug up on systematics will find that they are
>reading *The Wrong Books.*
Only if they do not understand what they are reading. You have to frame
your question to deal with that phylogeny and the limits that it imposes.
Sure you can ask all kinds of questions (why are my eyes brown? why does
my earlobe attach to the side of my face? why can I not taste PTC),
however those question only become testable and indeed useful when put
into a phylogenetic context. Let us take for example hairlessness, you
ask why we have less hair than chimps, the obvious phylogenetic question
(and the data has been pointed out to you in multiple posts) is what is
the distribution of hair in hominids? Hairlessness is only interesting
if it is an autapomorphy (probably) and is only usefull to you if it
occurred early (pre-australopith) (possible but untestable). Notice that
it is possible that hairlessness occured early, however the actual
distribution of this character is as follows
orang (lots)
gorilla (lots, but less than monkeys)
chimps (lots, but less than monkeys)
lca (?)
Australopithecus (?)
Paranthropus (?)
Homo habilis (?)
Homo erectus (?)
"primitive" Homo sapiens (?)(by primitive I mean pre-anatomically modern)
Homo sapiens neanderthalensis (?)
Homo sapiens sapiens (little)
(My apologies for the weird taxonomy, this is entirely off the top of
my head)
What pattern can we derive? none!!! Are you actually saying that you
can fill in all of those (?) because you said so? Why should I believe
that? Some form of divine inspiration?
You consistently misunderstand this basic point. You want to assume
the placement of all of these characters to fit your hypothesis and
I want no hypothesis that is dependant on those assumptions.
>Systematics only tells you about your pedigree up to the l.c.a.
>Paramorphics throws light on what happened to your species since that
>time, and may throw light on the cause of speciation. For instance, in
>the cases quoted in the first paragraph, the paramorphy tells you that
>all these species moved north. If you told a biologist"I have
>discovered a new species of lemmings, and they are white", you would
>not have to disclose where they came from. The biologist would be ready
>to give odds of twenty to one that they came from the arctic. To
>discover the reason for our own unusally rich collection of
>autapomorphies, the most promising method is to seek for
>paramorphic developments in other unrelated species.
Read my first section of questions. Is it actually correct to assume
they moved north? Maybe the environment got colder? Isn't that a
novel concept?
>So while I wish you every success, David Froehlich, in your chosen
>branch of science, I hope you will like a good American grant me
>the inalienable right to life, liberty, and the pursuit of
>paramorphies
Yes you can do whatever you please, just don't expect me to take you
seriously, or for that matter any of the AAH if that is the attitude
you want to take.
Implicit in this entire statement is the assumption that ontogeny
recapitulates phylogeny. Please read some systematics to understand
why this is a bad point of view to take.
Specifically, although I hate to recomend a Gould book, read Ontogeny and
Phylogeny.
Is it possible that some change occured that truncated the development
of hair?
Once again, AAH is a hypothesis in search of data, not data in search of an
hypothesis.
David J. Froehlich Phone: 512-471-6088
Vertebrate Paleontology Laboratory Fax: 512-471-5973
J.J. Pickle Research Campus
The University of Texas, Austin, Texas 78712
William Baird
>
>Consider this cluster of autapomorphies.
>
>The whiteness of the polar bear is unique among bears i.e. it is an
>autapomorphy.
Actually, no it's not. There is an island in Russia(??) where there is a
subspecies of the Black bear that 1 in 4 (IIRC) are white. The locals
refer to it as teh 'Ghost Bear'.
Will
>Elaine.
Will Baird email: wba...@nmsu.edu http://essex.nmsu.edu/~scomputi/
Phantoms! Whenever I think I fully understand mankind's purpose on earth...
suddenly I see phantoms dancing in the shadows...[saying] pointly as words,
"What you know is nothing little man; what you have to learn, immense." - CD
HARRY R. ERWIN
What I think you would like to do is use known patterns of character
evolution to reconstruct ancestral states.
Generally, you're proposing to use patterns of character evolution in
species A to parse out the probable patterns of character evolution
leading to the distantly related species, B, in the presence of the same
selection gradients. This is a different issue from that addressed by the
cladistic phylogeneticists, who treat the patterns of characters in the
data as syntactic evidence for different relationship trees, ignoring the
'meaning' of the characters.
Their approach was taken to an extreme by molecular phylogeneticists,
where it became clear that the 'meaning' of the characters had to be taken
into account due to the frequency of parallel evolution in closely related
taxa. I.e., characters that are evolving in response to some strong
selective gradient are _not_ good evidence for ancestry.
To do what you want to do for characteristics with no fossil evidence, you
will actually have to use two techniques:
1. For characteristics that you can show are under strong selective pressure,
you can use evidence of parallel evolution, and in fact you will probably
get better results than if you don't, since this is the area where the
cladistic technique fails.
2. For characteristics that are not under strong selective pressure,
cladistic techniques do better than analogy from parallel evolution.
However, you need some valid way of estimating 'selective pressure' to be
able to make this choice between techniques. Once you've done that, you
can't just extrapolate individual characteristics back in time because
noise will rapidly grow to dominate your results. You have to evolve the
full system backwards, a much harder piece of work. You can make this
approach work, but only very carefully and with suitable respect for your
data and the limitations of your models.
--
Harry Erwin
Internet: her...@gmu.edu
Web Page: http://osf1.gmu.edu/~herwin (contains 'indecent' academic material)
PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"
Lecturer for CS 211 (advanced C++)
chris brochu
Ela...@desco.demon.co.uk writes:
>Consider this cluster of autapomorphies.
>
>The whiteness of the polar bear is unique among bears i.e. it is an
>autapomorphy. So is the whiteness or seasonal whiteness of the ermine
>among mustelids, the arctic fox among
>canids, the arctic hare among lagomorphs. There is clearly some kind of
>pattern there that is trying to tell us something. (in this case
>something glaringly obvious).
>
We have statistical techniques for testing whether this is actually
"glaringly obvious" or not. I direct your attention to a book by Harvey
and Pagel entitled "The Comparative Method in Evolutionary Biology," of
which my copy is AWOL, so I cannot give you the full reference. There
are several papers by these authors, mostly dealing with continuous
characters; and another by Maddison describing similar procedures for
discrete characters. Again, these aren't with me at the moment.
In short, it is not enough to note that disparate lineages have the same
features to deduce common adaptive strategy. What we need to do is map
these traits on a tree - and this is where we cladists absolutely do not
ignore autapomorphies - and do some statistics on their correlation. We
note ALL occurrences of the traits in question - for example, white fur
and living near snow - and see if a statistically meaningful pattern can
be deduced.
In the case of white pelage and habitat, I suspect a positive pattern
will be found. But is this always to be the case? How about the
descended larynx? So far, I've seen reference to this character in
Sirenia and Homo sapiens - this is effectively two points, and one cannot
derive a meaningful result from this. Do other animals have descended
larynxes? Are they universally aquatic?
I'll try to pull the full references later.
chris
ps - I agree with David - Peramorphosis already has an established
meaning in systematics.
In the example
jam...@hgu.mrc.ac.uk
A human
>fetus recapitulates some of the earlier stages of our
>evolutionary journey e.g. at one time it has a tail, at one time its
>face and body are covered with hair. But it takes some time for new
>developments to be incorporated into the prenatal repertoire.
>
>I would guess that the unborn human begins shedding its body hair at
>around the same stage of gestation that the unborn chimp begins to
>develop knuckle pads; and that this suggests we have been naked about
>as long as the apes have been knuckle-walkers. I cannot prove this . It
>is a speculation. But the first half of it at least is testable.
>
Interesting....
You say that human babies are born much fatter than chimpanzee babies, at
what stage in its development does a human baby start to lay down this
extra fat? From your arguments we would expect it to do so at the same
time it starts shedding body hair.
We would also expect, in our evolutionary history, that the larynx
descended before we were capable of speech, if AAT is correct. But the
larynx doesn't descend in human development until after the baby has been
born, so how does this fit with the above? If this is all correct you
can't say that all of these features evolved at the same time.
Hairlessness and fatness maybe evolved at the same time, but other
adaptations must have come along later in the story.
James Borrett.
Phillip Bigelow
>
>Consider this cluster of autapomorphies.
>
>The whiteness of the polar bear is unique among bears i.e. it is an
>autapomorphy. So is the whiteness or seasonal whiteness of the ermine
>among mustelids, the arctic fox among
>canids, the arctic hare among lagomorphs. There is clearly some kind of
>pattern there that is trying to tell us something. (in this case
>something glaringly obvious).
>But if you are a systematist and focus your attention on construction
>cladograms, there is no way you can represent that pattern. In your
>diagrams it disappears from view.
Granted. But a cladist wouldn't be analyzing lagomorphs and carnivorans
on the same tree anyway!
While what you say is true, it is important to point out that
the convergent character traits in the above-mentioned taxa are
clearly-defined and no ambiguities exist in the observations. It is also
important to point out that the so-called "convergent" character traits
that you claim marine creatures and humans share are, in reality *very*
ambiguous, and have not been rigorously studied for errors. Yet, you
wrote two books on the AAT, while all the while inplying to your
readership that these character traits are unambiguous.
>You have words for genetical resemblances - plesiomorphic,
>symplesiomorphic - but no word for the striking resembance between the
>coats of those unrelated mammals.
It's called "convergence", Elaine.
> I suggest "paramorphic". It may be
>objected that I am talking about the old familiar cocept of convergent
>evolution, but that phrase does not readily adapt into an adjective,
Adjective: "Convergent coat color"
How's that?
Better yet, why not just a noun: "Convergence".
Used in a sentence: "The character trait of white seasonal fur is a
convergence".
>(I think paramorphic means something
>in physics, but that will not lead to any confusion. Anyway
>plesiomorph was already a word before the cladists borrowed it)
>
>If I ask why I so closely resemble a chimpanzee (as we all do ) the
>systematists can go a long way towards answering me by constructing a
>family tree. If I ask why I am nevertheless so different from a
>chimpanzee (as we all are) they are dumb.
A good systematicists would ask you for your list of derived traits,
and then they would go down the list and point out which ones are
actually plesiomorphies, and which ones are still unknown, and then hand
your list back to you and tell you to go back and re-check your facts.
The derived traits that you got right would impress them, but they would
probably point out that any given trait, or group of traits, doesn't
*necessarily* point to a discrete causual factor. Undoubtably, some
unique specializations will have a myriad of unrelated causes (it isn't
required, of course, but it certainly can't be ruled out). In fact,
evolutionary biologists such as Gould have hypothesized that speciation
by acquisition of random unique character traits may have an important
role in radiation.
>They only glance at the autapomorphies long enough to ensure
>themselves they can be safely shuffled out of the way and forgotten
>about.
Not quite. It is imperative to code for plesiomorphies as well.
Awareness of which traits are obviously convergence is also crucial, even
though those traits are not used in the analysis. You are vastly
over-simplifying the cladistic process.
>
>But the second question is the one I wish to address. I might borrow
>the current technical term for this frame of mind, and say I do not
>care a flying rat's ass why I resemble a chimpanzee; I want to know why
>I am different.
That is your agenda, and you are entitled to it. Your loyal supporters
are also entitled to share this same agenda. But the basis of your
statement, in fact, the very *foundation* of your statement, sounds
suspiciously ego-centric to me. More specifically, it sounds
suspiciously "specio-centric". The question also appears very
religiously-inspired. I realize that you fully believe in evolution. But
your frenzied need to break us off the Primate tree (with all of it's
wonderful-primate plesiomorphies), and your rush to separate us from the
native environment of our other primate ancestors, all seem to be
ignoring humanity's greatest drama...that we are *part* of a wonderfully
diverse continuum of life, with more similarities than differences. I
fully agree with you that humans have a lot of apomorphies. But,so what?
EVERY uniquely-named taxon has a set of apomorphies. That is how they
were named in the first place! Where I fail to agree with you is whether
these apomorphies are convergences with non-related taxa. I don't buy
that part.
>And I suggest that anyone asking that question and
>following the advice to mug up on systematics will find that they are
>reading *The Wrong Books.*
There are no *Wrong Books*, Elaine...just inaccurate interpretations
taken out of those books. You can't expect a cladistic systematicist to
be a paleo-ecologist (which is what you are inferring here). But you CAN
expect an clastic systematicist to point out to you which traits are
plesiomorphies and which are apomorphies. You might want to try talking
to some primate cladists some time, and see how many of your so-called
"paramorphies" (convergences) are, in fact, plesiomorphies.
You can learn a lot from a knowledgeable cladist. Try it sometime.
>Systematics only tells you about your pedigree up to the l.c.a.
>Paramorphics throws light on what happened to your species since that
>time, and may throw light on the cause of speciation.
I beg to differ. What you consider to be unique features for humans
(such as long head hair), would inspire a systematicist to point out that
long head hair is a variable trait *within* Homo sapiens sapiens, and as
such, does not imply a *diagnostic* character trait for our species. If
it is variable, then you cannot make such a generalization. Furthermore,
the systematicist would also point out to you that, if long head hair is
a variable trait, there is even less chance that it is an inherited trait
from earlier Homo populations (although the chance still exists, because
long-head-hair may in fact be, unknowingly, the primitive condition).
The same can be said for body hair distribution and body fat %, which
is also race-dependant (variable).
It is not the systematicist's job to tell you these things, (their
primary job is to work out ancestor-descendant relationships). But they
can point out factual errors in other biological disciplines when the
need arises.
>If you told a biologist"I have
>discovered a new species of lemmings, and they are white", you would
>not have to disclose where they came from. The biologist would be ready
>to give odds of twenty to one that they came from the arctic. To
>discover the reason for our own unusally rich collection of
>autapomorphies, the most promising method is to seek for
>paramorphic developments in other unrelated species.
Provided you are able to distinguish a convergent character from a
plesiomorphy, and provided you are not over-generalizing what character
is "uniquely human amongst the primates". Most of the characters you
claim are "unique" in fact haven't been rigorously and systematically
tabulated for other primate taxa. "Rigorously" is the key word, here.
>I hope you will like a good American grant me
>the inalienable right to life, liberty, and the pursuit of
>paramorphies
More accurately put, "pursuit of convergent characters".
But,make sure that your "convergent characters" don't turn out to be
symplesiomorphies or "presently-unknowns". You have been known to make
that mistake from time to time, haven't you? :-)
<pb>
Phillip Bigelow
>
>Consider this cluster of autapomorphies.
>
>The whiteness of the polar bear is unique among bears i.e. it is an
>autapomorphy. So is the whiteness or seasonal whiteness of the ermine
>among mustelids, the arctic fox among
>canids, the arctic hare among lagomorphs. There is clearly some kind of
>pattern there that is trying to tell us something. (in this case
>something glaringly obvious).
>But if you are a systematist and focus your attention on construction
>cladograms, there is no way you can represent that pattern. In your
>diagrams it disappears from view.
Granted. But a cladist wouldn't be analyzing lagomorphs and carnivorans
on the same tree anyway!
While what you say is true, it is important to point out that
the convergent character traits in the above-mentioned taxa are
clearly-defined and no ambiguities exist in the observations. It is also
important to point out that the so-called "convergent" character traits
that you claim marine creatures and humans share are, in reality *very*
ambiguous, and have not been rigorously studied for errors. Yet, you
wrote two books on the AAT, while all the while inplying to your
readership that these character traits are unambiguous.
>You have words for genetical resemblances - plesiomorphic,
>symplesiomorphic - but no word for the striking resembance between the
>coats of those unrelated mammals.
It's called "convergence", Elaine.
> I suggest "paramorphic". It may be
>objected that I am talking about the old familiar cocept of convergent
>evolution, but that phrase does not readily adapt into an adjective,
Adjective: "Convergent coat color"
How's that?
Better yet, why not just a noun: "Convergence".
Used in a sentence: "The character trait of white seasonal fur is a
convergence".
>(I think paramorphic means something
>in physics, but that will not lead to any confusion. Anyway
>plesiomorph was already a word before the cladists borrowed it)
>
>If I ask why I so closely resemble a chimpanzee (as we all do ) the
>systematists can go a long way towards answering me by constructing a
>family tree. If I ask why I am nevertheless so different from a
>chimpanzee (as we all are) they are dumb.
A good systematicists would ask you for your list of derived traits,
and then they would go down the list and point out which ones are
actually plesiomorphies, and which ones are still unknown, and then hand
your list back to you and tell you to go back and re-check your facts.
The derived traits that you got right would impress them, but they would
probably point out that any given trait, or group of traits, doesn't
*necessarily* point to a discrete causual factor. Undoubtably, some
unique specializations will have a myriad of unrelated causes (it isn't
required, of course, but it certainly can't be ruled out). In fact,
evolutionary biologists such as Gould have hypothesized that speciation
by acquisition of random unique character traits may have an important
role in radiation.
>They only glance at the autapomorphies long enough to ensure
>themselves they can be safely shuffled out of the way and forgotten
>about.
Not quite. It is imperative to code for plesiomorphies as well.
Awareness of which traits are obviously convergence is also crucial, even
though those traits are not used in the analysis. You are vastly
over-simplifying the cladistic process.
>
>But the second question is the one I wish to address. I might borrow
>the current technical term for this frame of mind, and say I do not
>care a flying rat's ass why I resemble a chimpanzee; I want to know why
>I am different.
That is your agenda, and you are entitled to it. Your loyal supporters
are also entitled to share this same agenda. But the basis of your
statement, in fact, the very *foundation* of your statement, sounds
suspiciously ego-centric to me. More specifically, it sounds
suspiciously "specio-centric". The question also appears very
religiously-inspired. I realize that you fully believe in evolution. But
your frenzied need to break us off the Primate tree (with all of it's
wonderful-primate plesiomorphies), and your rush to separate us from the
native environment of our other primate ancestors, all seem to be
ignoring humanity's greatest drama...that we are *part* of a wonderfully
diverse continuum of life, with more similarities than differences. I
fully agree with you that humans have a lot of apomorphies. But,so what?
EVERY uniquely-named taxon has a set of apomorphies. That is how they
were named in the first place! Where I fail to agree with you is whether
these apomorphies are convergences with non-related taxa. I don't buy
that part.
>And I suggest that anyone asking that question and
>following the advice to mug up on systematics will find that they are
>reading *The Wrong Books.*
There are no *Wrong Books*, Elaine...just inaccurate interpretations
taken out of those books. You can't expect a cladistic systematicist to
be a paleo-ecologist (which is what you are inferring here). But you CAN
expect an clastic systematicist to point out to you which traits are
plesiomorphies and which are apomorphies. You might want to try talking
to some primate cladists some time, and see how many of your so-called
"paramorphies" (convergences) are, in fact, plesiomorphies.
You can learn a lot from a knowledgeable cladist. Try it sometime.
>Systematics only tells you about your pedigree up to the l.c.a.
>Paramorphics throws light on what happened to your species since that
>time, and may throw light on the cause of speciation.
I beg to differ. What you consider to be unique features for humans
(such as long head hair), would inspire a systematicist to point out that
long head hair is a variable trait *within* Homo sapiens sapiens, and as
such, does not imply a *diagnostic* character trait for our species. If
it is variable, then you cannot make such a generalization. Furthermore,
the systematicist would also point out to you that, if long head hair is
a variable trait, there is even less chance that it is an inherited trait
from earlier Homo populations (although the chance still exists, because
long-head-hair may in fact be, unknowingly, the primitive condition).
The same can be said for body hair distribution and body fat %, which
is also race-dependant (variable).
It is not the systematicist's job to tell you these things, (their
primary job is to work out ancestor-descendant relationships). But they
can point out factual errors in other biological disciplines when the
need arises.
>If you told a biologist"I have
>discovered a new species of lemmings, and they are white", you would
>not have to disclose where they came from. The biologist would be ready
>to give odds of twenty to one that they came from the arctic. To
>discover the reason for our own unusally rich collection of
>autapomorphies, the most promising method is to seek for
>paramorphic developments in other unrelated species.
Provided you are able to distinguish a convergent character from a
plesiomorphy, and provided you are not over-generalizing what character
is "uniquely human amongst the primates". Most of the characters you
claim are "unique" in fact haven't been rigorously and systematically
tabulated for other primate taxa. "Rigorously" is the key word, here.
>I hope you will like a good American grant me
>the inalienable right to life, liberty, and the pursuit of
>paramorphies
Jim Moore
PB > While what you say is true, it is important to point out that
PB >the convergent character traits in the above-mentioned taxa are
PB >clearly-defined and no ambiguities exist in the observations. It is
also
PB >important to point out that the so-called "convergent" character
traits
PB >that you claim marine creatures and humans share are, in reality
*very*
PB >ambiguous, and have not been rigorously studied for errors. Yet, you
PB >wrote two books on the AAT, while all the while inplying to your
PB >readership that these character traits are unambiguous.
That's four books... so far.
>You have words for genetical resemblances - plesiomorphic,
>symplesiomorphic - but no word for the striking resembance between the
>coats of those unrelated mammals.
PB> It's called "convergence", Elaine.
> I suggest "paramorphic". It may be
>objected that I am talking about the old familiar cocept of convergent
>evolution, but that phrase does not readily adapt into an adjective,
PB> Adjective: "Convergent coat color"
PB> How's that?
PB> Better yet, why not just a noun: "Convergence".
PB> Used in a sentence: "The character trait of white seasonal fur is
a
PB> convergence".
The ironic thing about this conversation is that the AAT relies
heavily on the principle of covergent evolution, or at least the
phrase convergent evolution.
That said, it must also be noted that the AAT's version of
convergent evolution doesn't always quite match the principle
everyone else uses, so I thought I'd insert a definition of this
principle:
Robert L. Carroll (in *Vertebrate Paleontology and Evolution* 1988;
W.H. Freeman and Company: New York) pg. 7 says:
"Characters that are similar in structure and function but have
arisen separately rather than from a common ancestor are termed
*convergent*."
And he uses G.G. Simpson's description of the terms "convergence"
and the similar term "parallelism":
"Convergence is the development of similar characters separately in
two or more lineages without a common ancestry pertinent to the
similarity. Parallelism is the development of similar characters
separately in two or more lineages of common ancestry on the basis
of, or channeled by, characteristics of that ancestry."
The part of the principle which the AAT shies from is that these
convergent characters are similar in function. For example, one
of the chief claims of the AAT is that hominids have essentially
no body hair because of an aquatic past. There are, of course,
several problems with this which I'm not getting into here, such
as the facts that a great many humans have a lot of body hair and
that a great many aquatic mammals do as well.
What I am pointing out here is that the AAT tends to shy away from
describing any similarity in function in this characteristic
between humans and supposedly similarly endowed aquatic mammals.
Hardy, to his credit, recognised the necessity of doing this and
made a (not very convincing) attempt to do so; other AAT proponents
simply ignore this step.
EM> But the second question is the one I wish to address. I might borrow
EM> the current technical term for this frame of mind, and say I do not
EM> care a flying rat's ass why I resemble a chimpanzee; I want to know
why
EM> I am different.
If Elaine really wants to know that, and not just make a case for
her pet theory, she had better start being more rigorous in her
research; arguing "like a lawyer", which she admits is her method,
will not accomplish this goal.
PB> EVERY uniquely-named taxon has a set of apomorphies. That is how
they
PB> were named in the first place!
This point, one which seems lost on the AAT's proponents, is what
was behind the title of Robert Foley's book *Another Unique
Primate*.
Jim Moore e-mail: j#d#.mo...@canrem.com