You admit that because it so difficult for fossilization to occur,
there are only a handful of possible transitionals evidenced. I asked
you AGAIN, since the DNA cannot be analyized and the nice artists'
renderings of these creatures were based on a tooth here, a knee-
joint there, where is the PROOF that these things were not a different
species that merely shared charecteristics of another?
Why wouldn't a transitional be a different speicies that shared
characteristics of another?
If you're pretending not to be a creationist, you're doing it very badly.
> You admit that because it so difficult for fossilization to occur,
> there are only a handful of possible transitionals evidenced. I asked
> you AGAIN, since the DNA cannot be analyized and the nice artists'
> renderings of these creatures were based on a tooth here, a knee-
> joint there, where is the PROOF that these things were not a different
> species that merely shared charecteristics of another?
Proof isn't something science does, so let's substitute "good evidence".
First, it's hardly true that there are only a handful of transitionals.
There are, at least, hundreds, or perhaps thousands depending on just
what you would count. Nor are they made from a tooth here, a knee-joint
there; many transitional fossils are known from nearly complete
specimens, sometimes a great many such specimens. Finally, we need to
know what a transitional fossil is and what it isn't. What it isn't is
the descendant of species A and the ancestor of species C (call that B).
We would have to be very lucky to find such a thing, and would have no
way to recognize it anyway. What it is is a descendant of that unknown
species B that retains some of the characteristics of B that have been
lost in C, and that tells us what B was like. It would resemble A in
some ways (primitive features), C in some ways (derived features) be
intermediate in some ways, and probably have some of its own features,
unique to the branch it's on.
So what's the evidence that transitionals really are transitional? Well,
all these organisms make a pattern called a nested hierarchy, and the
pattern is strong enough that we can't possibly attribute it to chance,
as you seem to be trying to do. If one species shares enough
characteristics with another, we must suppose there is some reason for
that, and common ancestry provides the only reason that fits the data.
Transitional fossils fit nicely into the existing hierarchy. This is why
Tiktaalik, for instance, is such powerful evidence for evolution. Its
existence and features were predicted before it was found.
So jumping back to the past, what would someone examining the fossil
record of a similar relationship see? They find fossils of horses,
donkeys and mules. Whether or not the three are separate species would
be debated first, I'm sure, but let's say the scientists work past
that and determine that the 3 fossils do in fact represent different
species. Where is the transitional species?
I'll play along that this is some third person talking though you.
Tell this third person that is exactly what a transitional species is,
and so no PROOF is required. I suspect this third person is confused
by creationists' false claims that transitional species are supposed
to be direct lineal ancestors. For example, there was recently found
a reasonably complete fossil of a fish with legs, wrists, and fingers,
called Tiktaalik. Although scientists rightly declared it a
transitional form, they all expressly recognized that Tiktaalik was
likely only indrectly related to the line that ultimately gave rise to
tetrapods. So when an even older fossil tetrapod trackway was
discovered, scientists understood it didn't affect the status of
Tiktaalik. OTOH the Discovery Institute and its paid mouthpieces
tripped all over themselves claiming the one "disproved" the other,
while conveniently forgetting the fact that both fossils are evidence
of fish with legs which lived hundreds of millions of years ago.
Yes.
Your question is so simple minded, and wrong, it never should have been
posted.
Thank for the help!...No, it was not I who had the questions, but
someone I was having a discussion with.
???????????
Horses and donkeys ARE transitional.
Unless you happen to think evolution totally stopped yesterday!
Either it is known, OR it hasn't been discovered yet.
Not having specific answers for creationist's ignorant questions does
NOTHING to change the reality of evolution.
Using the mule as an example, is totally fraudulent.
Since cross breeding, for the most part, results in unreproducable animals -
evolution happens more because of changes, over a LONG time, in one
"species".
So I think one should always be patient to start with, even when we see
what look like the familiar signs of dissimulation.
[...]
--
Mike.
So the transitional species between a horse and a mule is a....?
And the transitional species between a donkey and a mule is a....?
> Not having specific answers for creationist's ignorant questions does
> NOTHING to change the reality of evolution.
Hybridization directly to a new species does not contradict evolution.
> Using the mule as an example, is totally fraudulent.
> Since cross breeding, for the most part, results in unreproducable animals -
For species, yes. For subspecies, no. Viable crossbreeding of species
is rare, but as anyone who defends evolution will tell you, evolution
has a lot of time and species to play with. Hybridization of
subspecies will produce the more gradual changes expected by Evolution
101 students.
> evolution happens more because of changes, over a LONG time, in one
> "species".
Some evolution, true. But not all. Thus, there will be some instances
where a clear transitional species will never be indentified. If you
are going to defend evolution, please learn it first. Or at least lay
off the all-caps and inapproriate quotes until you have the knowledge
to back it up. I grow tired of fighting side-by-side with screaming
buffoons.
I am personally interested in any future developments you might have
with this discussion.
Aside from the point that your correspondent's characterization of fossil
evidence is wrong, it is also apparently focused exclusively on megafauna.
Since life is much more diverse than megafauna, try considering other types
of fossil evidence.
Among diatomite (fossil diatoms), fossil plant pollen, or fossil
invertebrates, there is far more than a "handful of possible transitionals
evidenced." You might try referring to Fortey's excellent book _Trilobite:
Witness to Evolution_ for example. Or you could google "diatom evolution",
"pollen evolution", "trilobite evolution",
No it isn't. And they aren't. It's not that only a few mules have viable
offspring; there are only a few viable mule offspring, and the same pair
won't produce them reliably.
> So jumping back to the past, what would someone examining the fossil
> record of a similar relationship see? They find fossils of horses,
> donkeys and mules. Whether or not the three are separate species would
> be debated first, I'm sure, but let's say the scientists work past
> that and determine that the 3 fossils do in fact represent different
> species. Where is the transitional species?
Do you understand that hybrid speciation is fairly rare, especially in
animals? Using it as a model for what to expect in the fossil record is
very bad practice.
From wiki...
Since 1527 there have been more than 60 documented cases of foals born
to female mules around the world. There are reports that a mule in
China produced a foal in 1984. In Morocco, in early 2002, a mare mule
produced a rare foal. In 2007 a mule named Kate gave birth to a mule
son in Colorado. Blood and hair samples were tested verifying that the
mother was a mule and the colt was indeed her offspring.
> Do you understand that hybrid speciation is fairly rare, especially in
> animals? Using it as a model for what to expect in the fossil record is
> very bad practice.
Yes, very rare. So is speciation, the rarity of which is used by
creationists to argue that evolution doesn't exist. The rarity of the
occurance does not negate the occurance. With the long times involved
in evolution, the occurance of the rare is expected.
So the transition from ape to human, in which the reduction of two
acrocentric chromosomes into one metacentric chromosome is required...
do you think those two acrocentric chromosomes gradually melded into
one metacentric chromosome? Widdled down over generations? Two
acrocentric chromosomes can combine into one metacentric chromosome
(with the loss of a centromere) in one cell division, one generation.
This rapid change would leave a location in the fossil record where no
clear transitional species is evident.
That isn't in doubt. The question is whether if you mated the same pair
again they would produce offspring, and whether their offspring would
produce offspring. And I don't think that's the case. Reproduction is a
rare event, and remains so. This is not a characteristic that you can
use to produce a freely reproducing mule species.
>> Do you understand that hybrid speciation is fairly rare, especially in
>> animals? Using it as a model for what to expect in the fossil record is
>> very bad practice.
>
> Yes, very rare. So is speciation, the rarity of which is used by
> creationists to argue that evolution doesn't exist. The rarity of the
> occurance does not negate the occurance. With the long times involved
> in evolution, the occurance of the rare is expected.
You need to consider not just whether events are rare, but also their
relative rarity. Hybrid speciation in animals is much, much less common
than ordinary allopatric speciation, to the point where it's silly to
bring it up. (There are a very few clear examples, and another few
claimed examples, out of all the millions of animal species.)
> So the transition from ape to human, in which the reduction of two
> acrocentric chromosomes into one metacentric chromosome is required...
> do you think those two acrocentric chromosomes gradually melded into
> one metacentric chromosome?
No. But you make two mistakes here: you assume that chromosomal fusion
has something to do with speciation, and that it was somehow required in
the transition from ape to human. I don't think either of these is true.
> Widdled down over generations? Two
> acrocentric chromosomes can combine into one metacentric chromosome
> (with the loss of a centromere) in one cell division, one generation.
> This rapid change would leave a location in the fossil record where no
> clear transitional species is evident.
True. But then again it also wouldn't be speciation. Whatever makes you
think speciation and chromosomal fusion are in any way connected?
OK, l'see...
> You admit that because it so difficult for fossilization to occur,
This is true, on the whole.
> there are only a handful of possible transitionals evidenced.
Actually there are quite a few. The transition between species (e.g.
between home erectus and modern humans are uncommon on the whole. but
transitional series between higher *taxa (e.g. from lobe-finned fish
to amphibians, or dinosaurs to birds) are impessive and difficult to
deny. (Especially considerin gtheir distribution geologically and
chronologically. This page has many, with links:
http://www.talkorigins.org/faqs/faq-transitional.html
See also:
http://www.actionbioscience.org/evolution/benton2.html
http://www.nature.com/nature/newspdf/evolutiongems.pdf
> I asked
> you AGAIN, since the DNA cannot be analyized and the nice artists'
> renderings of these creatures were based on a tooth here, a knee-
> joint there,
A couple of comments. First, the fossils are often very complete. See
the recent tiktaalik, for example:
http://tinyurl.com/yj9stxt
http://tinyurl.com/ykdd9wr
Second, we can tell quite a bit about small portions of an animal,
especially if it's a type of animal we are familiar with. We may not
know what an organism ate, but if it's a bipedal ape, we know much
about how it walked, its size, its legs and pelvis and back, etc. We
may not know anything about its teeth and brain size (although we
would know that it was smarter than a turtle).
A portion of a bird's wing tell us much about how it flew (or if it
didn't), its size, etc. And the fossil is found in an environment that
says a lot. Shubin and his buddy looked for tiktaalik where they did
*because of the environment at the time and place, as well as its age.
> where is the PROOF that these things were not a different
Science doesn't look for proof; absolute certainty can only be found
in closed systems of logic - like arithmetic. When scientists have a
body of related evidence, they develop testable models that fit all
the known evidence. They are testable *because they make predictions
("If X is true, then if we look here we should find Y").
A transitional fossil is a fossil of an organism that has intermediate
features or a mix of features from a previous and a successive
organism. It may be a direct descendant/ancestor, or it may be that
descendant/ancestor's cousin. If it has the expected features at the
right time, it is transitional. If the features are somewhat
unexpected, then the model has to be changed. When we found Ardi a
little while back, we had to modify the story of human evolution. But
not dramatically; this would be as if we discovered evidence that
Julius Caesar's mother had actually been French. It would be
surprising, but it wouldn't call into question the overall story of
the Roman Republic and Empire.
> species that merely shared charecteristics of another?
It's not just a few characteristics; it's thousands (how many
characteristics does a femur have?). And millions of species. There is
no alternative testable model to explain the nested hierarchy. We
don't simply share characteristics with other species; the sharing
forms a pattern that allows only one way to sort us out and categorize
living species. The nested pattern looks like what we would get if
there was a common ancestor, modified over time and diversifying. The
fossils match this pattern, with the characteristics expected for the
time. Also, they are distributed in ways which match the change in
climate over time, as well as the movement of the continents and rise
and fall of the oceans. It;s a compelling picture for anyone who looks
at even a small fraction of the evidence.
Kermit
Correct, the existence of a few mules that produce viable offspring is
not evidence that there could someday be multitudes of mules producing
viable offspring. You have to extrapolate, hypothesize,... you know,
think.
> You need to consider not just whether events are rare, but also their
> relative rarity. Hybrid speciation in animals is much, much less common
> than ordinary allopatric speciation, to the point where it's silly to
> bring it up. (There are a very few clear examples, and another few
> claimed examples, out of all the millions of animal species.)
Yes, much less common. Gradual changes within a chromosome = frequent.
Changes in number of chromosomes = less frequent. The endosymbiosis of
entire genomes (mitochondria and chloroplasts) = extremely less
frequent, so lets just pretend it can't be used to explain the
evolution of the cells we see today.
> No. But you make two mistakes here: you assume that chromosomal fusion
> has something to do with speciation, and that it was somehow required in
> the transition from ape to human. I don't think either of these is true.
You think that the reduction of two acrocentric chromosomes in apes to
one metacentric chromosomes in humans is not required to get from ape
to human? Are you daft?
> True. But then again it also wouldn't be speciation. Whatever makes you
> think speciation and chromosomal fusion are in any way connected?
Oh fuck, I don't know, maybe that a monumental rearrangement to the
genetic code of a cell could lead to a new species. What the hell
would ever give me that idea?
You really aren't understanding. It's not a few mules that produce
viable offspring. It's a few cases in which individual mules have
produced a single viable offspring. Not a regular thing, even with those
particular mules. This is not an incipient species.
>> You need to consider not just whether events are rare, but also their
>> relative rarity. Hybrid speciation in animals is much, much less common
>> than ordinary allopatric speciation, to the point where it's silly to
>> bring it up. (There are a very few clear examples, and another few
>> claimed examples, out of all the millions of animal species.)
>
> Yes, much less common. Gradual changes within a chromosome = frequent.
> Changes in number of chromosomes = less frequent. The endosymbiosis of
> entire genomes (mitochondria and chloroplasts) = extremely less
> frequent, so lets just pretend it can't be used to explain the
> evolution of the cells we see today.
You are unusually condescending for a person who doesn't seem to know
much about the subject.
>> No. But you make two mistakes here: you assume that chromosomal fusion
>> has something to do with speciation, and that it was somehow required in
>> the transition from ape to human. I don't think either of these is true.
>
> You think that the reduction of two acrocentric chromosomes in apes to
> one metacentric chromosomes in humans is not required to get from ape
> to human? Are you daft?
It's required to the same degree that a change in some random neutral
site from G to C is required. I.e., it happened. Would we be any more or
less human if that change had not happened? No.
>> True. But then again it also wouldn't be speciation. Whatever makes you
>> think speciation and chromosomal fusion are in any way connected?
>
> Oh fuck, I don't know, maybe that a monumental rearrangement to the
> genetic code of a cell could lead to a new species. What the hell
> would ever give me that idea?
I don't know. It's wrong. Chromosomal fusion didn't affect phenotype at
all, as far as any one can tell. Nor did it cause reproductive
isolation. There are many species for which similar fusions are
polymorphic within populations. This has nothing to do with speciation,
and nothing to do with making us different from other apes (except for
the mere fact of the fusion).
No, it didn't, but what, exactly, are horses and donkeys transitional
between? I think you'd have to wait a few million years and see if there
are some new equid species around as all moder Equus species are
currently crown members in their clade.
Given that there have only been 60 recorded fertile mule mares in the
last ~500 years and no fertile mule stallions, I think it's a bit of a
stretch to say that the mule is a viable species.
To make it even more clear, in the USA alone in the 1920s and 1930s
there between 5 and 6 million mules, and 60 fertile females in 500 years
is 1 every 8 years, *globally*, not just the US. In the early 1900s in
the Poitou region in France, apparently 38000 mules were foale annually.
So, actually, it's one very big stretch to call mules a viable species,
what with no fertile stallions and exceedingly extremely rare fertile mares.
There are no 'transitional' species, only 'intermediate' ones. No
species is permanent, all are in a state of flux.
Speciation by hybridization is rare in animals because there are
serious impediments to successful hybridization. Are you familiar with
all the reproductive isolating mechanisms in animals? They start with
behavioral (wrong courtship song, wrong pheromone) and ecological
(different habitats) and mechanical (wrong-shaped genitalia) and
temporal (diurnal vs. nocturnal) and progress to gametic (wrong
hyaluronidase) and hybrid sterility (as we see in mules) and hybrid
breakdown (like we see in some warbler hybrids that crop up every few
years). That a few mules can produce a few offspring every few years
is not evidence they are a viable species.
Chris
What rearrangement? If you put three separated stamps on a large
envelope, and the same three types of stamps, with two attached two each
other, on another envelope, is there a massive rearrangement of postage?
Klaus
Would you agree that hybridization is the rarer, atypical process?
> So the transition from ape to human, in which the reduction of two
> acrocentric chromosomes into one metacentric chromosome is required...
> do you think those two acrocentric chromosomes gradually melded into
> one metacentric chromosome? Widdled down over generations? Two
> acrocentric chromosomes can combine into one metacentric chromosome
> (with the loss of a centromere) in one cell division, one generation.
> This rapid change would leave a location in the fossil record where no
> clear transitional species is evident.
The most likely scenario is that this translocation event happened
once in a single individual, and then spread by normal reproduction
throughout the population over several generations. However, neither
the immediate event or the gradual spreading would have left any
fossil evidence. Even if someone were to inadvertently come across a
humanoid fossil from the right time period, and even if they put a
thin section under a microscope, the chromosomes would be too
decomposed to count.
Actually, it's not all that monumental. Think about it. All the
genetic material is still there. Nothing is duplicated. Everything
can still line up with the original model during fertilization. In
fact, the current consensus is that this particularly translocation
has no effect on the phenotype.
Indeed. But the mule remains a bad example. You not only need mules
which produce viable offspring, but mules which produce fertile
offspring (that are mules).
The first problem is that they are no recorded fertile male mules; all
the viable offspring are backcrosses. The second is that there seems to
be something odd about meiosis in fertile mules. It appears that a molly
passes on her maternal genes, rather than a mixture of maternal and
paternal genes.
To muddy the waters a little, there are "species" with hemiclonal
transmission of genomes. The best known is the edible frog, Rana (or
Pelophylax) esculenta - "the hemiclonal frog Rana esculenta (E) which is
originally a hybrid between the sexual species R. lessonae (L) and R.
ridibunda (R). Rana esculenta excludes the L genome prior to meiosis,
produces eggs or sperm containing an unrecombined R genome and restores
hybridity by mating with R. lessonae (‘hybridogenesis’)"
(http://www.springerlink.com/content/1107123r732u05v3/). There are also
fish (hemiclonal Poeciliopsis, Squalius alburnoides), stick insects
(Bacillus whitei)
Rana esculenta is quite complex - there are LE and RE diploids (which
are arguably, at least in the absence of triploids, different species),
2 triploid cytotypes, and perhaps even tetraploids.
* Christiansen, Gamete types, sex determination and stable equilibria of
all-hybrid populations of diploid and triploid edible frogs (Pelophylax
esculentus), BMC Evolutionary Biology 9:135 (2009).
[<URL:http://www.biomedcentral.com/content/pdf/1471-2148-9-135.pdf>]
>
>> Using the mule as an example, is totally fraudulent.
>> Since cross breeding, for the most part, results in unreproducable animals -
>
>For species, yes. For subspecies, no. Viable crossbreeding of species
>is rare, but as anyone who defends evolution will tell you, evolution
>has a lot of time and species to play with. Hybridization of
>subspecies will produce the more gradual changes expected by Evolution
>101 students.
>
>> evolution happens more because of changes, over a LONG time, in one
>> "species".
>
>Some evolution, true. But not all. Thus, there will be some instances
>where a clear transitional species will never be indentified. If you
>are going to defend evolution, please learn it first. Or at least lay
>off the all-caps and inapproriate quotes until you have the knowledge
>to back it up. I grow tired of fighting side-by-side with screaming
>buffoons.
>
--
alias Ernest Major
I second that recommendation, Fortey's "Trilobite: Witness to
Evolution" is far more readable than the title suggests. I was
expecting a dry academic book on trilobites and was very pleasantly
surprised by the content.
--
sapient_...@spamsights.org ICQ #17887309 * Save the net *
Grok: http://spam.abuse.net http://www.cauce.org * nuke a spammer *
Find: http://www.samspade.org http://www.netdemon.net * today *
Kill: http://mail-abuse.com http://au.sorbs.net http://spamhaus.org
Nope. John is correct. It is not required.
About 1:1000 humans alive today have a fused chromosome, they are not
another species and can interbreed with humans with normal chromosome
counts (although there may be a higher percentage of chromosome
abnormalities in their children).
http://www.sapientfridge.org/chromosome_count/index.html
In a way , everything is a transitional species.
Its a matter of listing the characteristics and placing it in the
place those characteristics dictate. Then taking the datings available
it may be shown that A was present first, C came later, and new B fits
in between.
I always thought mules were sterile.
I can add to that. It isn't enough for a mule to produce offspring.
That offspring has to be able to mate with something and so on down
the line.
The best chance for survival is to have a group become isolated
and long-term change take place within the group. That way
there remains an excellent chance for reproduction.
--
--- Paul J. Gans
> This below came up regarding transitional species....I'm sure its a
> simple answer.
Questions have answers: what you posted, claiming it is a
question, is an assertion--- not a question. Nobody here falls for
that ploy.
> You admit that because it so difficult for fossilization to occur,
> there are only a handful of possible transitionals evidenced. I asked
> you AGAIN, since the DNA cannot be analyized and the nice artists'
> renderings of these creatures were based on a tooth here, a knee-
> joint there, where is the PROOF that these things were not a different
> species that merely shared charecteristics of another?
--
http://desertphile.org
Desertphile's Desert Soliloquy. WARNING: view with plenty of water
"Why aren't resurrections from the dead noteworthy?" -- Jim Rutz
"Lotta soon to die punks here." -- igotskillz22
>
> <tapeh...@yahoo.com> wrote in message
> news:41a55132-7a07-48f2...@m37g2000yqf.googlegroups.com...
> > This below came up regarding transitional species....I'm sure its a
> > simple answer.
> Yes.
> Your question is so simple minded, and wrong, it never should have been
> posted.
It ain't even a question: it is an assertion made under the
pretense of asking a question. I.e., typical Creationist behavior.
Are you taking the piss?
[...]
--
Mike.
Was it an evolution-denier, or just someone who misunderstands
science? If the former, has he/she offered a potentially better
explanation, or just incredulity? If the former, does that explanation
include common descent, as some evolution-deniers concede? And does it
agree or disagree with mainstream science chronology - IOW the age if
not the "transitional" nature of the fossils in question?
If the former.... or if the former....
Hmmmm
The masked typist avenger strikes again!
Before mechanization came along and rendered mules far less valuable
there was a great deal of incentive for a breeder to produce a freely
reproducing mule species. And people did try, and fail. I doubt that
the science of breeding equines has advanced enough, if at all, to
make such an achievement at all likely in the future.
--
Will in New Haven
> aganunitsi wrote:
> > On Mar 12, 1:49 pm, John Harshman <jharsh...@pacbell.net> wrote:
...
>
> >> Do you understand that hybrid speciation is fairly rare, especially in
> >> animals? Using it as a model for what to expect in the fossil record is
> >> very bad practice.
> >
> > Yes, very rare. So is speciation, the rarity of which is used by
> > creationists to argue that evolution doesn't exist. The rarity of the
> > occurance does not negate the occurance. With the long times involved
> > in evolution, the occurance of the rare is expected.
>
> You need to consider not just whether events are rare, but also their
> relative rarity. Hybrid speciation in animals is much, much less common
> than ordinary allopatric speciation, to the point where it's silly to
> bring it up. (There are a very few clear examples, and another few
> claimed examples, out of all the millions of animal species.)
I wonder if there isn't a confirmation bias in play here? We haven't
taken hybridisation seriously as an evolutionary phenomenon until
relatively recently, and only a few researchers have been looking for
the signature (e.g., Jim Mallett). But as we do go looking for signals
of introgression, we find them with a fairly constant frequency.
Possibly we will find that speciation has occurred involving (note: not
necessarily due to) hybridisation more as we look for it.
As late as the 1970s, Mayr and others were saying that hybridisation
doesn't matter - now we find, largely on molecular grounds, that it is
rampant (my WAG is around 20-40% of animal species have introgression
in their immediate past). Of course, this is like the
allopatry/sympatry dispute and may turn in the end on semantics, but I
suspect that lateral transfer will turn out to be quite crucial in a
lot of speciation, even if direct hybridisation is not the reason for
the speciation as in the Brassica case.
Like I said, WAGgery
...
Let's not confuse introgression with hybrid speciation. There's plenty
of evidence for introgression in a host of species pairs. But none of it
is hybrid speciation. Be clear on the meaning: a hybrid species arises
as the offspring of two species, which thereafter forms its own breeding
population. (I'm not sure what to call "species" that exist only as a
population of F1 hybrids, or that are obligate outcrossers with one of
the original species, but I wouldn't exactly call it hybrid speciation
either.)
> As late as the 1970s, Mayr and others were saying that hybridisation
> doesn't matter - now we find, largely on molecular grounds, that it is
> rampant (my WAG is around 20-40% of animal species have introgression
> in their immediate past). Of course, this is like the
> allopatry/sympatry dispute and may turn in the end on semantics, but I
> suspect that lateral transfer will turn out to be quite crucial in a
> lot of speciation, even if direct hybridisation is not the reason for
> the speciation as in the Brassica case.
Can you explain how lateral transfer can be crucial in speciation, and
give evidence that it is commonly such?
aganunitsi seems wedded to the idea that mules are a viable species.
If the mule is a viable species, we should have seen it happening by
now- or at least, we should have seen mules mating with one another
before now, at a greater rate than he's described. The very few
successful matings are not enough to sustain a new species. There
might be the potential for it in, as you say, a highly isolated and
circumscribed population. But that's not what we have, is it....
Chris
Nor would I. But botanists know that it happens, and so I would expect
that there would be similar cases in animals, even if a lot fewer
cases.
They call them "nothospecies", by the way.
>
> > As late as the 1970s, Mayr and others were saying that hybridisation
> > doesn't matter - now we find, largely on molecular grounds, that it is
> > rampant (my WAG is around 20-40% of animal species have introgression
> > in their immediate past). Of course, this is like the
> > allopatry/sympatry dispute and may turn in the end on semantics, but I
> > suspect that lateral transfer will turn out to be quite crucial in a
> > lot of speciation, even if direct hybridisation is not the reason for
> > the speciation as in the Brassica case.
>
> Can you explain how lateral transfer can be crucial in speciation, and
> give evidence that it is commonly such?
>
Introgression can change the overall genetic variance of a peripheral
isolate, so I guess that can affect the likelihood that the population
will speciate. As to the second question, no. That was my point about
confirmation bias.
That is not the normal usage among botanists. A nothotaxon is just
another name for a hybrid (see ICBN). Species of hybrid origin are
usually just species.
A term of tangential relevance is compilospecies.
--
alias Ernest Major
I meant to say compilospecies (plunderer of other species). My mistake.
But Herb Wagner, who coined the term "nothospecies", intended it to
mean species formed by hybridisation. I know this, because he told me
himself.
"Nosuchspecies"? Cool! Are they also called "speciesinblack"? You
biologists keep me eternally surprised.
There are in fact a few known cases. But introgression is irrelevant to
the question.
> They call them "nothospecies", by the way.
>>> As late as the 1970s, Mayr and others were saying that hybridisation
>>> doesn't matter - now we find, largely on molecular grounds, that it is
>>> rampant (my WAG is around 20-40% of animal species have introgression
>>> in their immediate past). Of course, this is like the
>>> allopatry/sympatry dispute and may turn in the end on semantics, but I
>>> suspect that lateral transfer will turn out to be quite crucial in a
>>> lot of speciation, even if direct hybridisation is not the reason for
>>> the speciation as in the Brassica case.
>> Can you explain how lateral transfer can be crucial in speciation, and
>> give evidence that it is commonly such?
>>
> Introgression can change the overall genetic variance of a peripheral
> isolate, so I guess that can affect the likelihood that the population
> will speciate.
Perhaps, though, you would like to step down from that word "crucial"?
> As to the second question, no. That was my point about
> confirmation bias.
I have my doubts. Introgression is a well-studied phenomenon. If it were
commonly important in speciation, I think we would have noticed.
But since you are a 'bloody accomodationist' when it comes to the use or
spelling of words, you know that intent is of no value when people get
hold of something.
The intentional fallacy is not a fallacy...
> We know that donkeys and horses can be bred to
> generate a new species, the mule.
Mules are a species now?
Equus mulus, dumbus assus.
http://justfuckinggoogleit.com/
The concept of species is too indefinite for that question to have a
single correct answer.
On no account of what species are is there a mule species.
But surely there's a mule kind.
Mules propagate poorly and rarely, if at all, with other mules, and one
necessary criterion for a mammalian *species* is that its members
propagate with their own kind.
I always forget, there's no sarcasm that might not be mistaken for a
creationist speaking seriously.
I think Bill was being Ironic, referring to creationists.
Yes, there is a kind of things called Mules; which is why we have the
name for that kind. As a card-carrying nominalist (a particular card,
in my case a card that gets me discounts at Colorado stores; well, at
particular stores that have a name "Colorado" on the shopfront... damn
it's hard being a consistent nominalist) I deny the reality of the
class "mule", and accept only that we are disposed to call horse-donkey
hybrids mules.
And Virgil is entirely correct. Mammals have species by being able to
interbreed fertile progeny, and so a mule is not a member of a single
species. The way groups have species is a unique evolved series of
traits, and for mammals that includes breeding behaviours.
AFAIK, only a few primates use money. There is one species of monkey
that uses tokens from their keepers and exchanges them for fruit or the
males give to females in exchange for sex.
--
A computer without Microsoft is like a chocolate cake without mustard.
One cannot parody creationism, because if one tries and come up with a
really original idea, a creationist will adopt it as part of his
ideology.
OTOH, a particular thought of mine, "The ark must have been nuclear
powered. because that was the only way the ark could have maintained
headway and grow enough food for the animals,", does not seem to have
been taken up by any creationist that I know of.
Seriously, dude, mules do not meet the strict definition
of "species," as they can't reproduce.
> JTEM <jte...@gmail.com> wrote:
>
> > aganunitsi <ssyke...@mindspring.com> wrote:
> > > We know that donkeys and horses can be bred to
> > > generate a new species, the mule.
>
> > Mules are a species now?
>
> The concept of species is too indefinite for that question
> to have a single correct answer.
Ordinarily I would agree with you. But, mules can't reproduce.
Some mules can. Even in the Nineteenth Century the question was how to
get mules that bred _reliably_ and with other mules and not to get any
to breed at all. If someone had achieved it he probably would have
made a large fortune out of it.
I wouldn't call them a species but I wouldn't say someone who called
them a species was necessarily wrong.
"Will in New Haven" <bill....@taylorandfrancis.com> wrote in message
news:23991cb6-8086-4d43...@b7g2000yqd.googlegroups.com:
Maybe mules should be called a species perpetually on the verge of
extinction, since they are unable to reproduce in anywhere near the
numbers needed to maintain themselves without their numbers being
constantly refreshed by horse-donkey matings.
-- Steven L.
"JTEM" <jte...@gmail.com> wrote in message
news:1d1004ab-9e67-4834...@q23g2000yqd.googlegroups.com:
There are rare (fewer than 100) documented cases of female mules having
offspring.
-- Steven L.
But never with male mules.
Apparently the extreme few females that can reproduce don't pass along a
recombinant mixture of horse and donkey genes but the full set from the
mother only. Hemiclonal transmission.
According to evolutionary theory, all species are transitional----it's
just so because Genesis is not an option. Gaps or missing evidence is
not a problem because Genesis, like I said, is not an option for
Atheists.
How far would a Biblical argument get if the writer said what Darwin
said: "the evidence is missing, but it should be there."
Why was a theory with no evidence in support accepted?
For now we can say that it was due to hatred of the Bible and the God
portrayed therein.
Ray
>On Mar 12, 12:35 pm, tapehead...@yahoo.com wrote:
>> This below came up regarding transitional species....I'm sure its a
>> simple answer.
>>
>> You admit that because it so difficult for fossilization to occur,
>> there are only a handful of possible transitionals evidenced. I asked
>> you AGAIN, since the DNA cannot be analyized and the nice artists'
>> renderings of these creatures were based on a tooth here, a knee-
>> joint there, where is the PROOF that these things were not a different
>> species that merely shared charecteristics of another?
>
>According to evolutionary theory, all species are transitional----it's
>just so because Genesis is not an option. Gaps or missing evidence is
>not a problem because Genesis, like I said, is not an option for
>Atheists.
>
>How far would a Biblical argument get if the writer said what Darwin
>said: "the evidence is missing, but it should be there."
Yes, but Darwin was predicting the evidence that would be found if his
theory were accurate and he was right. I guess you've had
150-years'-worth of scientific discovery hidden from you.
>Why was a theory with no evidence in support accepted?
It has evidence to support it. Whoever told you otherwise lied to you.
>For now we can say that it was due to hatred of the Bible and the God
>portrayed therein.
You can say that, but you would be repeating a falsehood. Science has
nothing to do with the Bible or with God. If you don't like the
discoveries of science, it's because you preach false doctrines.
Where is the evidence for Genesis, moron. Genesis doesn't have enough
evidence to have gaps.
> How far would a Biblical argument get if the writer said what Darwin
> said: "the evidence is missing, but it should be there."
The people making Biblical arguments say no evidence is necessary.
That way they don't have to come up with any.
> Why was a theory with no evidence in support accepted?
Virtually the entire science of biology is evidence for evolution.
Where is the evidence for evolution?
> For now we can say that it was due to hatred of the Bible and the God
> portrayed therein.
It is very possible to find something unconvincing without hating it.
Do you hate the Koran, the Book of Mormon?
Nor is it an option for anyone who prefers to rely on empirical data
rather than revelation. Now it would have been conceivable for the
empirical data to tell the same story as the bible, in which case one
might believe in the truth of the biblical story; even an atheist could
do that. But that's not how the data turned out.
> How far would a Biblical argument get if the writer said what Darwin
> said: "the evidence is missing, but it should be there."
Nowhere, one would hope. But of course Darwin never actually said that.
> Why was a theory with no evidence in support accepted?
Which theory was that? Not evolution, there being plenty of evidence
now, and even plenty of evidence then.
> For now we can say that it was due to hatred of the Bible and the God
> portrayed therein.
Are you posting in partnership with your tapeworm? Otherwise, who are
"we"? Nobody who is being honest and who knows anything about history
would say that.
> I wouldn't call them a species but I wouldn't say someone
> who called them a species was necessarily wrong.
There. Now you've confused me, which is a good thing.
I've long heard that unless you're confused over where
the lines between separate species are drawn, you don't
understand a damn thing.
Talk about a Catch 22...
Ken Ham apparently considers Genesis the only option, and still
(implicitly) concludes that all species are transitional.
>
>How far would a Biblical argument get if the writer said what Darwin
>said: "the evidence is missing, but it should be there."
Among bibliolators, a long way.
>
>Why was a theory with no evidence in support accepted?
Because of worship of the Bible. (I presume that you are talking about
Creationism.)
>
>For now we can say that it was due to hatred of the Bible and the God
>portrayed therein.
Yes, you can lie, and we can keep reminding you of Exodus 20: 16.
And, it ill becomes someone who claims that the Epistle of James is
heretical to accuses other of hating the Bible.
>
>Ray
>
--
alias Ernest Major