Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Re: Setting the record straight about a _Science_ article on mammal evolution
30 views
Skip to first unread message
pnyikos
Feb 25, 2013, 3:56:09 PM2/25/13
to nyi...@bellsouth.net
I have added sci.bio.paleontology. This is the second post to this
thread in talk.origins; the first had to do with a little "intramural"
confusion exclusive to t.o.
On Feb 25, 2:59�pm, pnyikos <nyik...@bellsouth.net> wrote:
> In the February 8 issue of _Science_, an international team of
> researchers published a paper that is sure to ignite a lot of
> controversy among paleontologists and people in related fields. �This
> is because they place the last common ancestor of ALL living placental
> mammals after the extinction of the dinosaurs.
http://www.sciencemag.org/content/339/6120/662.full
The full article is paywalled, but perhaps the evolutionary tree
referenced at the end of this post is not.
What is especially noteworthy is that the authors do NOT reassess the
molecular evidence for this late date, but rely on fossil evidence
(and perhaps some sophisticated morphological thinking in the
supplementary article, which runs to 131 pages).
And yet, the following website, also in a supplement to a _Science_
article, claims the existence of a ca. 5-kilo condylarth and a
taenolabid of the same size from 105.5 mya:
http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
Taenolabids may or may not be placentals -- they have long been
extinct -- but condylarths were primitive placentals related to extant
ungulates.
Even if this critter turns out to have been mis-identified, it seems
very shaky to conclude from the dearth of clearly identifiable
Cretaceous placental mammals that the LCA lived after the K-T
extinction event.
Isn't the conventional wisdom about the Cambrian explosion that the
many phyla first appearing then had a long evolutionary history which
simply hasn't shown up in the fossils we have now? Why such a
different conclusion about the LCA of living placentals?
> The article places the LCA of the clade Placentalia in the Paleocene,
> while dating the eutherian - marsupial split all the way back to the
> Jurassic:
>
> http://www.sciencemag.org/content/339/6120/662/F1.large.jpg
This can be magnified further if the details are still hard to read.
Peter Nyikos
Professor, Dept. of Mathematics � � � -- standard disclaimer--
University of South Carolinahttp://www.math.sc.edu/~nyikos/
nyikos @ math.sc.edu
thread in talk.origins; the first had to do with a little "intramural"
confusion exclusive to t.o.
On Feb 25, 2:59�pm, pnyikos <nyik...@bellsouth.net> wrote:
> In the February 8 issue of _Science_, an international team of
> researchers published a paper that is sure to ignite a lot of
> controversy among paleontologists and people in related fields. �This
> is because they place the last common ancestor of ALL living placental
> mammals after the extinction of the dinosaurs.
http://www.sciencemag.org/content/339/6120/662.full
The full article is paywalled, but perhaps the evolutionary tree
referenced at the end of this post is not.
What is especially noteworthy is that the authors do NOT reassess the
molecular evidence for this late date, but rely on fossil evidence
(and perhaps some sophisticated morphological thinking in the
supplementary article, which runs to 131 pages).
And yet, the following website, also in a supplement to a _Science_
article, claims the existence of a ca. 5-kilo condylarth and a
taenolabid of the same size from 105.5 mya:
http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
Taenolabids may or may not be placentals -- they have long been
extinct -- but condylarths were primitive placentals related to extant
ungulates.
Even if this critter turns out to have been mis-identified, it seems
very shaky to conclude from the dearth of clearly identifiable
Cretaceous placental mammals that the LCA lived after the K-T
extinction event.
Isn't the conventional wisdom about the Cambrian explosion that the
many phyla first appearing then had a long evolutionary history which
simply hasn't shown up in the fossils we have now? Why such a
different conclusion about the LCA of living placentals?
> The article places the LCA of the clade Placentalia in the Paleocene,
> while dating the eutherian - marsupial split all the way back to the
> Jurassic:
>
> http://www.sciencemag.org/content/339/6120/662/F1.large.jpg
This can be magnified further if the details are still hard to read.
Peter Nyikos
Professor, Dept. of Mathematics � � � -- standard disclaimer--
University of South Carolinahttp://www.math.sc.edu/~nyikos/
nyikos @ math.sc.edu
John Harshman
Feb 25, 2013, 4:11:10 PM2/25/13
to
pre-Cambrian deposits that might or might not be stem-members of several
phyla. I believe there's been some discussion of the various possible
hypotheses of placental evolution: short fuse, long fuse, etc. And that
language was taken exactly from the literature on the Cambrian explosion.
> Why such a
> different conclusion about the LCA of living placentals?
mammals is better than the pre-explosion record of phyla and thus is
better able to constrain hypotheses. And I agree that this is true. But
is it true enough to enable us to draw firm conclusions? That's the
question.
pnyikos
Feb 25, 2013, 6:02:24 PM2/25/13
to nyi...@bellsouth.net
As long as I have you on the line, John, here is the bulk of a reply I
did to you on the thread where this _Science_ article was first
discussed earlier this month.
Did you lose track of the thread before Valentine's Day? You never
did reply, and some of what I wrote is still relevant to this thread.
Snips are marked with [...].
On Feb 8, 4:54 pLocal: Thurs, Feb 14 2013 9:42 pm
Subject: Re: Earliest placental mammal ancestor pinpointed
On Feb 8, 4:54 pm, John Harshman <jharsh...@pacbell.net> wrote:
> On 2/8/13 1:33 PM, Metspitzer wrote:
> > The creature that gave rise to all the placental mammals - a huge
> > group that includes whales, elephants, dogs, bats and us - has at last
> > been pinpointed.
> Urk. Science journalism at its worst.
Fortunately, there is a link in the article which takes you to an
abstract in the 8 February issue of Science.
> > An international effort mapped out thousands of physical traits and
> > genetic clues to trace the lineage.
> > Their results indicate that all placental mammals arose from a small,
> > furry, insect-eating animal.
A mountain labors and brings forth a mouse, er, a small furry insect
eating animal.
[Two out of three ain't bad.] :-)
The abstract is underwhelming. Specific "discoveries" are listed in
the second half:
"Many nodes discovered using molecular data are upheld, but phenomic
signals overturn molecular signals to show Sundatheria (Dermoptera +
Scandentia) as the sister taxon of Primates, a close link between
Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of
echolocating Chiroptera (bats). Our tree suggests that Placentalia
first split into Xenarthra and Epitheria; extinct New World species
are the oldest members of Afrotheria."
http://www.sciencemag.org/content/339/6120/662.abstract
[...]
[T]he only conclusion above that is the least bit surprising
is the last sentence. I always did wonder whether "Afrotheria"
is a well supported group.
> > A report in Science resolves the debate as to when the creature lived;
> > it came about after the demise of dinosaurs.
> This seems odd, considering the number of claimed Cretaceous placental
> fossils.
It also flies in the face of a huge number of estimates of divergence
time in that website you gave me on another thread, John.
http://www.timetree.org/
Entering "human" and "armadillo" I get an average date of divergence
of 104.1 million years, deep within the Cretaceous. Even two animals
as close as colugos ("flying lemurs") and bats get 94.4 mya.
The lead article of this thread in talk.origins [I've added
sci.bio.paleontology] has a lot of popularized talk about the
characters of the LCA of the crown group, but very little as to how
the dates were arrived at.
I wonder what the "clincher" in the report is supposed to be, the one
that sets aside all the research behind this website. The abstract
simply states a bald claim:
"Combining these data with molecular sequences, we obtained a
phylogenetic tree that, when calibrated with fossils, shows that
crown
clade Placentalia and placental orders originated after the K-Pg
boundary." [ibid.]
> Are they all outside the crown group? Maybe, but I'd like to
> see that backed up.
> No subscription to Science, unfortunately.
Our university library has one, and I might even be able to access it
online at my office. Here at home, it is paywalled.
================= end of text
By the way, it seems that the conclusion that Microchiroptera is a
clade is out of the mainstream: the other phylogenies I've seen today
have Megachiroptera as a clade, while "echolocating Chiroptera," as
the abstract puts it, is paraphyletic.
did to you on the thread where this _Science_ article was first
discussed earlier this month.
Did you lose track of the thread before Valentine's Day? You never
did reply, and some of what I wrote is still relevant to this thread.
Snips are marked with [...].
On Feb 8, 4:54 pLocal: Thurs, Feb 14 2013 9:42 pm
Subject: Re: Earliest placental mammal ancestor pinpointed
On Feb 8, 4:54 pm, John Harshman <jharsh...@pacbell.net> wrote:
> On 2/8/13 1:33 PM, Metspitzer wrote:
> > The creature that gave rise to all the placental mammals - a huge
> > group that includes whales, elephants, dogs, bats and us - has at last
> > been pinpointed.
> Urk. Science journalism at its worst.
Fortunately, there is a link in the article which takes you to an
abstract in the 8 February issue of Science.
> > An international effort mapped out thousands of physical traits and
> > genetic clues to trace the lineage.
> > Their results indicate that all placental mammals arose from a small,
> > furry, insect-eating animal.
A mountain labors and brings forth a mouse, er, a small furry insect
eating animal.
[Two out of three ain't bad.] :-)
The abstract is underwhelming. Specific "discoveries" are listed in
the second half:
"Many nodes discovered using molecular data are upheld, but phenomic
signals overturn molecular signals to show Sundatheria (Dermoptera +
Scandentia) as the sister taxon of Primates, a close link between
Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of
echolocating Chiroptera (bats). Our tree suggests that Placentalia
first split into Xenarthra and Epitheria; extinct New World species
are the oldest members of Afrotheria."
http://www.sciencemag.org/content/339/6120/662.abstract
[...]
[T]he only conclusion above that is the least bit surprising
is the last sentence. I always did wonder whether "Afrotheria"
is a well supported group.
> > A report in Science resolves the debate as to when the creature lived;
> > it came about after the demise of dinosaurs.
> This seems odd, considering the number of claimed Cretaceous placental
> fossils.
It also flies in the face of a huge number of estimates of divergence
time in that website you gave me on another thread, John.
http://www.timetree.org/
Entering "human" and "armadillo" I get an average date of divergence
of 104.1 million years, deep within the Cretaceous. Even two animals
as close as colugos ("flying lemurs") and bats get 94.4 mya.
The lead article of this thread in talk.origins [I've added
sci.bio.paleontology] has a lot of popularized talk about the
characters of the LCA of the crown group, but very little as to how
the dates were arrived at.
I wonder what the "clincher" in the report is supposed to be, the one
that sets aside all the research behind this website. The abstract
simply states a bald claim:
"Combining these data with molecular sequences, we obtained a
phylogenetic tree that, when calibrated with fossils, shows that
crown
clade Placentalia and placental orders originated after the K-Pg
boundary." [ibid.]
> Are they all outside the crown group? Maybe, but I'd like to
> see that backed up.
> No subscription to Science, unfortunately.
Our university library has one, and I might even be able to access it
online at my office. Here at home, it is paywalled.
================= end of text
By the way, it seems that the conclusion that Microchiroptera is a
clade is out of the mainstream: the other phylogenies I've seen today
have Megachiroptera as a clade, while "echolocating Chiroptera," as
the abstract puts it, is paraphyletic.
John Harshman
Feb 25, 2013, 6:49:05 PM2/25/13
to
On 2/25/13 3:02 PM, pnyikos wrote:
> As long as I have you on the line, John, here is the bulk of a reply I
> did to you on the thread where this _Science_ article was first
> discussed earlier this month.
>
> Did you lose track of the thread before Valentine's Day? You never
> did reply, and some of what I wrote is still relevant to this thread.
> Snips are marked with [...].
I don't see anything that demands a response, but if you really want
> As long as I have you on the line, John, here is the bulk of a reply I
> did to you on the thread where this _Science_ article was first
> discussed earlier this month.
>
> Did you lose track of the thread before Valentine's Day? You never
> did reply, and some of what I wrote is still relevant to this thread.
> Snips are marked with [...].
one, sure.
are still contentious. Afrotheria is not in the least controversial, but
Epitheria is.
>>> A report in Science resolves the debate as to when the creature lived;
>>> it came about after the demise of dinosaurs.
>
>> This seems odd, considering the number of claimed Cretaceous placental
>> fossils.
>
> It also flies in the face of a huge number of estimates of divergence
> time in that website you gave me on another thread, John.
>
> http://www.timetree.org/
There are also issues with the tree topology used (really, apparently, a
classification inferred to represent a tree).
> Entering "human" and "armadillo" I get an average date of divergence
> of 104.1 million years, deep within the Cretaceous. Even two animals
> as close as colugos ("flying lemurs") and bats get 94.4 mya.
>
> The lead article of this thread in talk.origins [I've added
> sci.bio.paleontology] has a lot of popularized talk about the
> characters of the LCA of the crown group, but very little as to how
> the dates were arrived at.
>
> I wonder what the "clincher" in the report is supposed to be, the one
> that sets aside all the research behind this website. The abstract
> simply states a bald claim:
>
>
> "Combining these data with molecular sequences, we obtained a
> phylogenetic tree that, when calibrated with fossils, shows that
> crown
> clade Placentalia and placental orders originated after the K-Pg
> boundary." [ibid.]
supplementary material, which should be free.
>> Are they all outside the crown group? Maybe, but I'd like to
>> see that backed up.
>
>> No subscription to Science, unfortunately.
>
> Our university library has one, and I might even be able to access it
> online at my office. Here at home, it is paywalled.
> ================= end of text
>
> By the way, it seems that the conclusion that Microchiroptera is a
> clade is out of the mainstream: the other phylogenies I've seen today
> have Megachiroptera as a clade, while "echolocating Chiroptera," as
> the abstract puts it, is paraphyletic.
is no necessary contradiction here. Nor do I know what phylogenies you
have seen today.
John S. Wilkins
Feb 25, 2013, 6:56:29 PM2/25/13
to
...
...
--
John S. Wilkins, Associate, Philosophy, University of Sydney
Honorary Fellow, University of Melbourne
- http://evolvingthoughts.net
> >>> A report in Science resolves the debate as to when the creature lived;
> >>> it came about after the demise of dinosaurs.
> >
> >> This seems odd, considering the number of claimed Cretaceous placental
> >> fossils.
> >
> > It also flies in the face of a huge number of estimates of divergence
> > time in that website you gave me on another thread, John.
> >
> > http://www.timetree.org/
>
> That's largely because almost all of those estimates are molecular.
> There are also issues with the tree topology used (really, apparently, a
> classification inferred to represent a tree).
John, have you turned to the Dark Transformed Side?
> >>> it came about after the demise of dinosaurs.
> >
> >> This seems odd, considering the number of claimed Cretaceous placental
> >> fossils.
> >
> > It also flies in the face of a huge number of estimates of divergence
> > time in that website you gave me on another thread, John.
> >
> > http://www.timetree.org/
>
> That's largely because almost all of those estimates are molecular.
> There are also issues with the tree topology used (really, apparently, a
> classification inferred to represent a tree).
...
--
John S. Wilkins, Associate, Philosophy, University of Sydney
Honorary Fellow, University of Melbourne
- http://evolvingthoughts.net
pnyikos
Feb 25, 2013, 7:49:13 PM2/25/13
to nyi...@bellsouth.net
On Feb 25, 6:49�pm, John Harshman <jharsh...@pacbell.net> wrote:
> On 2/25/13 3:02 PM, pnyikos wrote:
>
> > As long as I have you on the line, John, here is the bulk of a reply I
> > did to you on the thread where this _Science_ article was first
> > discussed earlier this month.
[snip]
> On 2/25/13 3:02 PM, pnyikos wrote:
>
> > As long as I have you on the line, John, here is the bulk of a reply I
> > did to you on the thread where this _Science_ article was first
> > discussed earlier this month.
> > Did you lose track of the thread before Valentine's Day? �You never
> > did reply, and some of what I wrote is still relevant to this thread.
> > Snips are marked with [...].
>
> I don't see anything that demands a response, but if you really want
> one, sure.
>
>
>
>
>
> > On Feb 8, 4:54 pLocal: Thurs, Feb 14 2013 9:42 pm
> > Subject: Re: Earliest placental mammal ancestor pinpointed
> > The abstract is underwhelming. Specific "discoveries" are listed in
> > the second half:
>
> > "Many nodes discovered using molecular data are upheld, but phenomic
> > signals overturn molecular signals to show Sundatheria (Dermoptera +
> > Scandentia) as the sister taxon of Primates, a close link between
> > Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of
> > echolocating Chiroptera (bats). Our tree suggests that Placentalia
> > first split into Xenarthra and Epitheria; extinct New World species
> > are the oldest members of Afrotheria."
>
> >http://www.sciencemag.org/content/339/6120/662.abstract
>
> > [...]
>
> > [T]he only conclusion above that is the least bit surprising
> > is the last sentence. �I always did wonder whether "Afrotheria"
> > is a well supported group.
>
> I disagree. The relationships among Scandentia, Dermopter, and Primates
> are still contentious.
I'm under the impression that this is almost a "trifurcation" [I
> > the second half:
>
> > "Many nodes discovered using molecular data are upheld, but phenomic
> > signals overturn molecular signals to show Sundatheria (Dermoptera +
> > Scandentia) as the sister taxon of Primates, a close link between
> > Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of
> > echolocating Chiroptera (bats). Our tree suggests that Placentalia
> > first split into Xenarthra and Epitheria; extinct New World species
> > are the oldest members of Afrotheria."
>
> >http://www.sciencemag.org/content/339/6120/662.abstract
>
> > [...]
>
> > [T]he only conclusion above that is the least bit surprising
> > is the last sentence. �I always did wonder whether "Afrotheria"
> > is a well supported group.
>
> I disagree. The relationships among Scandentia, Dermopter, and Primates
> are still contentious.
forget the technical term] so it's almost a flip (or two) of the coin
which two groups are grouped together. Since it is almost a heresy
among cladistic systematists to have trifurcations in a phylogenetic
tree, there is no cause for surprise IMHO.
> Afrotheria is not in the least controversial, but
> Epitheria is.
evidence, is it?
> > On Feb 8, 4:54 pm, John Harshman<jharsh...@pacbell.net> wrote:
>
> >> On 2/8/13 1:33 PM, Metspitzer wrote:
> > >> A report in Science resolves the debate as to when the creature lived;
> >>> it came about after the demise of dinosaurs.
>
> >> This seems odd, considering the number of claimed Cretaceous placental
> >> fossils.
>
> > It also flies in the face of a huge number of estimates of divergence
> > time in that website you gave me on another thread, John.
>
> >http://www.timetree.org/
>
> That's largely because almost all of those estimates are molecular.
besides Condylartha? I'm referring to the reference I gave in my
second post, which claimed the existence of a ca. 5-kilo condylarth
and a taenolabid of the same size from 105.5 mya:
http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
See bottom of page 4.
http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
> There are also issues with the tree topology used (really, apparently, a
> classification inferred to represent a tree).
[snip]
> > Entering "human" and "armadillo" I get an average date of divergence
> > of 104.1 million years, deep within the Cretaceous. �Even two animals
> > as close as colugos ("flying lemurs") and bats get 94.4 mya.
other site.
> >> � Are they all outside the crown group? Maybe, but I'd like to
> >> see that backed up.
>
> >> No subscription to Science, unfortunately.
>
> > Our university library has one, and I might even be able to access it
> > online at my office. �Here at home, it is paywalled.
> > ================= end of text
>
> > By the way, it seems that the conclusion that Microchiroptera is a
> > clade is out of the mainstream: the other phylogenies I've seen today
> > have Megachiroptera as a clade, while "echolocating Chiroptera," as
> > the abstract puts it, is paraphyletic.
>
> Microchiroptera is not synonymous with echolocating Chiroptera, so there
> is no necessary contradiction here. Nor do I know what phylogenies you
> have seen today.
Here is one of them, served up two different ways:
>
> >> No subscription to Science, unfortunately.
>
> > Our university library has one, and I might even be able to access it
> > online at my office. �Here at home, it is paywalled.
> > ================= end of text
>
> > By the way, it seems that the conclusion that Microchiroptera is a
> > clade is out of the mainstream: the other phylogenies I've seen today
> > have Megachiroptera as a clade, while "echolocating Chiroptera," as
> > the abstract puts it, is paraphyletic.
>
> Microchiroptera is not synonymous with echolocating Chiroptera, so there
> is no necessary contradiction here. Nor do I know what phylogenies you
> have seen today.
http://www.sciencemag.org/content/307/5709/580/F2.large.jpg
color coded wrt location:
http://www.sciencemag.org/content/307/5709/580/F3.large.jpg
As usual, the full article is paywalled. Here is a little excerpt:
"However, molecules reveal a sister-taxon relationship between the
rhinolophoid microbats and the megabats (Yinpterochiroptera),
suggesting either multiple origins of laryngeal echolocation within
bats or a single origin of echolocation with subsequent loss in
megabats (5) (10)."
[the microbats have the Yang prefix!]
The article leans towards the latter hypothesis, and goes on to
hypothesize that echolocation and powered flight co-evolved. It talks
about the "big bang" of bat diversification in the Eocene.
Peter Nyikos
John Harshman
Feb 25, 2013, 8:25:36 PM2/25/13
to
On 2/25/13 3:56 PM, John S. Wilkins wrote:
> John Harshman<jhar...@pacbell.net> wrote:
>
>> On 2/25/13 3:02 PM, pnyikos wrote:
> ...
>>>>> A report in Science resolves the debate as to when the creature lived;
>>>>> it came about after the demise of dinosaurs.
>>>
>>>> This seems odd, considering the number of claimed Cretaceous placental
>>>> fossils.
>>>
>>> It also flies in the face of a huge number of estimates of divergence
>>> time in that website you gave me on another thread, John.
>>>
>>> http://www.timetree.org/
>>
>> That's largely because almost all of those estimates are molecular.
>> There are also issues with the tree topology used (really, apparently, a
>> classification inferred to represent a tree).
>
> John, have you turned to the Dark Transformed Side?
> ...
No, but you may explain.
> John Harshman<jhar...@pacbell.net> wrote:
>
>> On 2/25/13 3:02 PM, pnyikos wrote:
> ...
>>>>> A report in Science resolves the debate as to when the creature lived;
>>>>> it came about after the demise of dinosaurs.
>>>
>>>> This seems odd, considering the number of claimed Cretaceous placental
>>>> fossils.
>>>
>>> It also flies in the face of a huge number of estimates of divergence
>>> time in that website you gave me on another thread, John.
>>>
>>> http://www.timetree.org/
>>
>> That's largely because almost all of those estimates are molecular.
>> There are also issues with the tree topology used (really, apparently, a
>> classification inferred to represent a tree).
>
> John, have you turned to the Dark Transformed Side?
> ...
John Harshman
Feb 25, 2013, 8:43:43 PM2/25/13
to
And no, it is neither a heresy nor almost a heresy.
>> Afrotheria is not in the least controversial, but
>> Epitheria is.
>
> So Afrotheria is supported by both molecular and morphological
> evidence, is it?
>>> On Feb 8, 4:54 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>
>>>> On 2/8/13 1:33 PM, Metspitzer wrote:
>
>>>>> A report in Science resolves the debate as to when the creature lived;
>>>>> it came about after the demise of dinosaurs.
>>
>>>> This seems odd, considering the number of claimed Cretaceous placental
>>>> fossils.
>>
>>> It also flies in the face of a huge number of estimates of divergence
>>> time in that website you gave me on another thread, John.
>>
>>> http://www.timetree.org/
>>
>> That's largely because almost all of those estimates are molecular.
>
> Aren't there claims of Mesozoic fossils from other eutherian groups
> besides Condylartha? I'm referring to the reference I gave in my
> second post, which claimed the existence of a ca. 5-kilo condylarth
> and a taenolabid of the same size from 105.5 mya:
> http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
>
> See bottom of page 4.
>
>
>> There are also issues with the tree topology used (really, apparently, a
>> classification inferred to represent a tree).
>
> And trees are the only way for you cladophiles to go, n'est-ce pas?
is merely a knee-jerk poke that lets you use the word "cladophile", and
that you didn't think about it at all.
>>> Entering "human" and "armadillo" I get an average date of divergence
>>> of 104.1 million years, deep within the Cretaceous. Even two animals
>>> as close as colugos ("flying lemurs") and bats get 94.4 mya.
>
> Note the similarity of the first figure to that 105.5 figure in the
> other site.
>>>> Are they all outside the crown group? Maybe, but I'd like to
>>>> see that backed up.
>>
>>>> No subscription to Science, unfortunately.
>>
>>> Our university library has one, and I might even be able to access it
>>> online at my office. Here at home, it is paywalled.
>>> ================= end of text
>>
>>> By the way, it seems that the conclusion that Microchiroptera is a
>>> clade is out of the mainstream: the other phylogenies I've seen today
>>> have Megachiroptera as a clade, while "echolocating Chiroptera," as
>>> the abstract puts it, is paraphyletic.
>>
>> Microchiroptera is not synonymous with echolocating Chiroptera, so there
>> is no necessary contradiction here. Nor do I know what phylogenies you
>> have seen today.
>
> Here is one of them, served up two different ways:
>
> http://www.sciencemag.org/content/307/5709/580/F2.large.jpg
> color coded wrt location:
> http://www.sciencemag.org/content/307/5709/580/F3.large.jpg
supplementary information, support is pretty good. I would like to have
seen some gene jackknifing and/or individual locus trees.
pnyikos
Feb 25, 2013, 8:59:42 PM2/25/13
to nyi...@bellsouth.net
On Feb 25, 6:56�pm, j...@wilkins.id.au (John S. Wilkins) wrote:
English?
By the way, it seems that extant birds are also widely believed to
have evolved from a single common post-KT ancestor. Here is a reply
to me back in 2000 by Harshman's old nemesis, Cal King:
In article <85dfl0$18...@theusc.csd.sc.edu>, nyi...@math.sc.edu (Peter
Nyikos) wrote:
> get...@nobull.net (Cal King) writes:
>
>>Since the radiation of modern orders occurred in the Tertiary, there really
>>isn't any incontrovertible Neornitheans in the Cretaceous. There were
>>numerous Ornithurine birds in the Cretaceous, but these were, according to
>>Feduccia, only "transitional shorebirds"
>
>What about the Charadriiformes? Kenneth Kinman says they
>are uncontroversial modern birds of the Cretaceous.
>
>Peter Nyikos -- standard disclaimer --
>Professor, Dept. of Mathematics
>University of South Carolina
>Columbia, SC 29208
Feduccia (1996) calls them "transitional shorebirds". This group
appeared to
have been the only group of birds to have survived the K-T holocaust.
My
speculation is that toothlessness is adaptive in the sand sifting
niche (no
sand will get between one's teeth if one has no teeth). Since the
transitional shorebirds are likely to be toothless, their status as
sole
survivors and ancestors of modern bird orders is the reason why all
modern
birds are toothless. From this group sprung the shorebird-modern
order
mosaics in the early Tertiary. The transitional shorebirds are
therefore
ancestral to the Neornithes, but not Neornitheans themselves.
========== end of included post,
Message-ID: <85fjp0$qsm$1...@bgtnsc02.worldnet.att.net>
Timely, eh? Harshman has been active on a thread he started, in which
he disses Feduccia.
Peter Nyikos
> John Harshman <jharsh...@pacbell.net> wrote:
> > On 2/25/13 3:02 PM, pnyikos wrote:
> ...
> > >>> A report in Science resolves the debate as to when the creature lived;
> > >>> it came about after the demise of dinosaurs.
>
> > >> This seems odd, considering the number of claimed Cretaceous placental
> > >> fossils.
>
> > > It also flies in the face of a huge number of estimates of divergence
> > > time in that website you gave me on another thread, John.
>
> > >http://www.timetree.org/
>
> > That's largely because almost all of those estimates are molecular.
> > There are also issues with the tree topology used (really, apparently, a
> > classification inferred to represent a tree).
>
> John, have you turned to the Dark Transformed Side?
John, would you mind putting that last comment into self-explanatory
> > On 2/25/13 3:02 PM, pnyikos wrote:
> ...
> > >>> A report in Science resolves the debate as to when the creature lived;
> > >>> it came about after the demise of dinosaurs.
>
> > >> This seems odd, considering the number of claimed Cretaceous placental
> > >> fossils.
>
> > > It also flies in the face of a huge number of estimates of divergence
> > > time in that website you gave me on another thread, John.
>
> > >http://www.timetree.org/
>
> > That's largely because almost all of those estimates are molecular.
> > There are also issues with the tree topology used (really, apparently, a
> > classification inferred to represent a tree).
>
> John, have you turned to the Dark Transformed Side?
English?
By the way, it seems that extant birds are also widely believed to
have evolved from a single common post-KT ancestor. Here is a reply
to me back in 2000 by Harshman's old nemesis, Cal King:
In article <85dfl0$18...@theusc.csd.sc.edu>, nyi...@math.sc.edu (Peter
Nyikos) wrote:
> get...@nobull.net (Cal King) writes:
>
>>Since the radiation of modern orders occurred in the Tertiary, there really
>>isn't any incontrovertible Neornitheans in the Cretaceous. There were
>>numerous Ornithurine birds in the Cretaceous, but these were, according to
>>Feduccia, only "transitional shorebirds"
>
>What about the Charadriiformes? Kenneth Kinman says they
>are uncontroversial modern birds of the Cretaceous.
>
>Peter Nyikos -- standard disclaimer --
>Professor, Dept. of Mathematics
>University of South Carolina
>Columbia, SC 29208
Feduccia (1996) calls them "transitional shorebirds". This group
appeared to
have been the only group of birds to have survived the K-T holocaust.
My
speculation is that toothlessness is adaptive in the sand sifting
niche (no
sand will get between one's teeth if one has no teeth). Since the
transitional shorebirds are likely to be toothless, their status as
sole
survivors and ancestors of modern bird orders is the reason why all
modern
birds are toothless. From this group sprung the shorebird-modern
order
mosaics in the early Tertiary. The transitional shorebirds are
therefore
ancestral to the Neornithes, but not Neornitheans themselves.
========== end of included post,
Message-ID: <85fjp0$qsm$1...@bgtnsc02.worldnet.att.net>
Timely, eh? Harshman has been active on a thread he started, in which
he disses Feduccia.
Peter Nyikos
John Harshman
Feb 25, 2013, 9:55:12 PM2/25/13
to
On 2/25/13 5:59 PM, pnyikos wrote:
> On Feb 25, 6:56 pm, j...@wilkins.id.au (John S. Wilkins) wrote:
>> John Harshman<jharsh...@pacbell.net> wrote:
>>> On 2/25/13 3:02 PM, pnyikos wrote:
>> ...
>>>>>> A report in Science resolves the debate as to when the creature lived;
>>>>>> it came about after the demise of dinosaurs.
>>
>>>>> This seems odd, considering the number of claimed Cretaceous placental
>>>>> fossils.
>>
>>>> It also flies in the face of a huge number of estimates of divergence
>>>> time in that website you gave me on another thread, John.
>>
>>>> http://www.timetree.org/
>>
>>> That's largely because almost all of those estimates are molecular.
>>> There are also issues with the tree topology used (really, apparently, a
>>> classification inferred to represent a tree).
>>
>> John, have you turned to the Dark Transformed Side?
>
> John, would you mind putting that last comment into self-explanatory
> English?
>
> By the way, it seems that extant birds are also widely believed to
> have evolved from a single common post-KT ancestor. Here is a reply
> to me back in 2000 by Harshman's old nemesis, Cal King:
However did you get from Cal King and Alan Feduccia to "widely believed"?
> On Feb 25, 6:56 pm, j...@wilkins.id.au (John S. Wilkins) wrote:
>> John Harshman<jharsh...@pacbell.net> wrote:
>>> On 2/25/13 3:02 PM, pnyikos wrote:
>> ...
>>>>>> A report in Science resolves the debate as to when the creature lived;
>>>>>> it came about after the demise of dinosaurs.
>>
>>>>> This seems odd, considering the number of claimed Cretaceous placental
>>>>> fossils.
>>
>>>> It also flies in the face of a huge number of estimates of divergence
>>>> time in that website you gave me on another thread, John.
>>
>>>> http://www.timetree.org/
>>
>>> That's largely because almost all of those estimates are molecular.
>>> There are also issues with the tree topology used (really, apparently, a
>>> classification inferred to represent a tree).
>>
>> John, have you turned to the Dark Transformed Side?
>
> John, would you mind putting that last comment into self-explanatory
> English?
>
> By the way, it seems that extant birds are also widely believed to
> have evolved from a single common post-KT ancestor. Here is a reply
> to me back in 2000 by Harshman's old nemesis, Cal King:
> Timely, eh? Harshman has been active on a thread he started, in which
> he disses Feduccia.
happen to think of by free association?
John S. Wilkins
Feb 26, 2013, 6:49:19 PM2/26/13
to
pnyikos <nyi...@bellsouth.net> wrote:
> Since it is almost a heresy
> among cladistic systematists to have trifurcations in a phylogenetic
> tree, there is no cause for surprise IMHO.
It's not heresy. It's a polytomy, which simply means that there is
> Since it is almost a heresy
> among cladistic systematists to have trifurcations in a phylogenetic
> tree, there is no cause for surprise IMHO.
insufficient data to make dichotomies. It's a statement of "insufficient
information to resolve". This is a virtue in a scientific discipline, I
woul dhave thought, that it refuses to make assertions in the basence of
evidence.
John S. Wilkins
Feb 26, 2013, 6:51:28 PM2/26/13
to
a tree.
John Harshman
Feb 26, 2013, 8:52:52 PM2/26/13
to
On 2/26/13 3:49 PM, John S. Wilkins wrote:
> pnyikos<nyi...@bellsouth.net> wrote:
>
>> Since it is almost a heresy
>> among cladistic systematists to have trifurcations in a phylogenetic
>> tree, there is no cause for surprise IMHO.
>
> It's not heresy. It's a polytomy, which simply means that there is
> insufficient data to make dichotomies. It's a statement of "insufficient
> information to resolve". This is a virtue in a scientific discipline, I
> woul dhave thought, that it refuses to make assertions in the basence of
> evidence.
There are two kinds of polytomies, called "hard" and "soft". You have
> pnyikos<nyi...@bellsouth.net> wrote:
>
>> Since it is almost a heresy
>> among cladistic systematists to have trifurcations in a phylogenetic
>> tree, there is no cause for surprise IMHO.
>
> It's not heresy. It's a polytomy, which simply means that there is
> insufficient data to make dichotomies. It's a statement of "insufficient
> information to resolve". This is a virtue in a scientific discipline, I
> woul dhave thought, that it refuses to make assertions in the basence of
> evidence.
described a soft polytomy, for which there are presumed real
relationships but insufficient data to resolve them. A hard polytomy is
a real multifurcation, i.e. a population splitting into three or more
chunks at the same time. (Obviously, the two grade into each other, but
the terminology is still handy.)
John S. Wilkins
Feb 26, 2013, 11:14:30 PM2/26/13
to
John Harshman
Feb 26, 2013, 11:29:49 PM2/26/13
to
On 2/26/13 8:14 PM, John S. Wilkins wrote:
> John Harshman<jhar...@pacbell.net> wrote:
>
>> On 2/26/13 3:49 PM, John S. Wilkins wrote:
>>> pnyikos<nyi...@bellsouth.net> wrote:
>>>
>>>> Since it is almost a heresy
>>>> among cladistic systematists to have trifurcations in a phylogenetic
>>>> tree, there is no cause for surprise IMHO.
>>>
>>> It's not heresy. It's a polytomy, which simply means that there is
>>> insufficient data to make dichotomies. It's a statement of "insufficient
>>> information to resolve". This is a virtue in a scientific discipline, I
>>> woul dhave thought, that it refuses to make assertions in the basence of
>>> evidence.
>>
>> There are two kinds of polytomies, called "hard" and "soft". You have
>> described a soft polytomy, for which there are presumed real
>> relationships but insufficient data to resolve them. A hard polytomy is
>> a real multifurcation, i.e. a population splitting into three or more
>> chunks at the same time. (Obviously, the two grade into each other, but
>> the terminology is still handy.)
>
> How do you know that a hard polytomy is hard?
If, after you have collected enough data, you still don't have clear
> John Harshman<jhar...@pacbell.net> wrote:
>
>> On 2/26/13 3:49 PM, John S. Wilkins wrote:
>>> pnyikos<nyi...@bellsouth.net> wrote:
>>>
>>>> Since it is almost a heresy
>>>> among cladistic systematists to have trifurcations in a phylogenetic
>>>> tree, there is no cause for surprise IMHO.
>>>
>>> It's not heresy. It's a polytomy, which simply means that there is
>>> insufficient data to make dichotomies. It's a statement of "insufficient
>>> information to resolve". This is a virtue in a scientific discipline, I
>>> woul dhave thought, that it refuses to make assertions in the basence of
>>> evidence.
>>
>> There are two kinds of polytomies, called "hard" and "soft". You have
>> described a soft polytomy, for which there are presumed real
>> relationships but insufficient data to resolve them. A hard polytomy is
>> a real multifurcation, i.e. a population splitting into three or more
>> chunks at the same time. (Obviously, the two grade into each other, but
>> the terminology is still handy.)
>
> How do you know that a hard polytomy is hard?
resolution. Of course, "enough data" is subjective. But it can be
quantified by simulation, which can put an upper bound on the time
between successive divergences. (The lower bound is of course zero.)
Also, if you get enough loci, you can test to see whether their
disagreements can be explained by lineage sorting with no bias toward
one tree. So there are ways, but they still involve a continuum, and
there is no objective dividing line.
John S. Wilkins
Feb 27, 2013, 2:55:00 AM2/27/13
to
is a statement that there is structure in the data. If there is none,
can you replace the lack of data with prior models of how evolution must
have proceeded?
drose...@yahoo.com
Feb 27, 2013, 11:02:09 AM2/27/13
to
What you call hard polytomy others may call parallel speciation is a distinct possibility. Speciation occurring in the same geological moment of time in different environments is highly likely because the earth has so many environments.
I thought that what you call "hard polytomy" is the basis of "species radiation" and "punctuated equilibrium". Punctuated equilibrium is a "species radiation" that comes after an extinction event. However, the sudden increase in the number of species caused by an increase in mutation rate.
The reason is that there is so much speciation going on after the extinction event there are lots of niches that are empty of organisms. Natural selection favors "pioneers" that explore these niches. If the extinction event is very short in time span, these new niches are all open and available at the same time. Therefore, it seems very likely that "hard polytomy" occurs after every short but intense extinction.
Also, speciation isn't instantaneous. "genusiation", "familiation", and "orderiation" probably take much longer than "speciation". So the meaning of "simultaneous" is a bit ambiguous, here. There are wide time windows where speciation and other "radiation" can occur.
On the species level, consider Rhagoletis (type of fruit fly, not drosophilia). Before Rhagoletis came to this country, the flies specialized in hawthorne fruit. Once they came here, they differentiated in a few decades to live on apples, blueberries and other fruit. Although some of the evolution came from bifurcations, these bifurcations were extremely close together in time.
Furthermore, some of the Rhagoletis differentiations may have been actually simultaneous. After all, the ability to interbreed vanished slowly. So for a while, there could have been a population of interbreeding flies that attacked hawthorne, apples and blueberries at the same time. The different varieties have lost most of their ability to interbreed. However, larvae can sometimes survive the occasional cross. So until they lose the ability to interbreed completely, the different varieties can still be considered as evolving "simultaneously".
Look at all the varieties of "flu" that evolve at the same time. Or HIV. "Hard polytomy" is common in microorganisms.
John Harshman
Feb 27, 2013, 11:19:24 AM2/27/13
to
On 2/27/13 8:02 AM, drose...@yahoo.com wrote:
> On Tuesday, February 26, 2013 8:52:52 PM UTC-5, John Harshman wrote:
>> On 2/26/13 3:49 PM, John S. Wilkins wrote:
>>
>>> pnyikos<nyi...@bellsouth.net> wrote:
>>
>>>
>>
>>>> Since it is almost a heresy
>>
>>>> among cladistic systematists to have trifurcations in a phylogenetic
>>
>>>> tree, there is no cause for surprise IMHO.
>>
>>>
>>
>>> It's not heresy. It's a polytomy, which simply means that there is
>>
>>> insufficient data to make dichotomies. It's a statement of "insufficient
>>
>>> information to resolve". This is a virtue in a scientific discipline, I
>>
>>> woul dhave thought, that it refuses to make assertions in the basence of
>>
>>> evidence.
>>
>>
>>
>> There are two kinds of polytomies, called "hard" and "soft". You have
>>
>> described a soft polytomy, for which there are presumed real
>>
>> relationships but insufficient data to resolve them. A hard polytomy is
>>
>> a real multifurcation, i.e. a population splitting into three or more
>>
>> chunks at the same time. (Obviously, the two grade into each other, but
>>
>> the terminology is still handy.)
> I don't see why a hard polytomy would be considered "heresy".
It wouldn't.
> On Tuesday, February 26, 2013 8:52:52 PM UTC-5, John Harshman wrote:
>> On 2/26/13 3:49 PM, John S. Wilkins wrote:
>>
>>> pnyikos<nyi...@bellsouth.net> wrote:
>>
>>>
>>
>>>> Since it is almost a heresy
>>
>>>> among cladistic systematists to have trifurcations in a phylogenetic
>>
>>>> tree, there is no cause for surprise IMHO.
>>
>>>
>>
>>> It's not heresy. It's a polytomy, which simply means that there is
>>
>>> insufficient data to make dichotomies. It's a statement of "insufficient
>>
>>> information to resolve". This is a virtue in a scientific discipline, I
>>
>>> woul dhave thought, that it refuses to make assertions in the basence of
>>
>>> evidence.
>>
>>
>>
>> There are two kinds of polytomies, called "hard" and "soft". You have
>>
>> described a soft polytomy, for which there are presumed real
>>
>> relationships but insufficient data to resolve them. A hard polytomy is
>>
>> a real multifurcation, i.e. a population splitting into three or more
>>
>> chunks at the same time. (Obviously, the two grade into each other, but
>>
>> the terminology is still handy.)
> I don't see why a hard polytomy would be considered "heresy".
> Different species of animals can evolve at the same time in different
> geographical locations, or even in different niches of the same
> location.
>
> What you call hard polytomy others may call parallel speciation is a
> distinct possibility. Speciation occurring in the same geological
> moment of time in different environments is highly likely because the
> earth has so many environments.
>
> I thought that what you call "hard polytomy" is the basis of "species
> radiation" and "punctuated equilibrium". Punctuated equilibrium is a
> "species radiation" that comes after an extinction event. However,
> the sudden increase in the number of species caused by an increase in
> mutation rate.
particular association with extinction events or an increase in mutation
rate. However, if we ignore the erroneous connection with PE, some of
what you say is true. So-called "adaptive radiations" are common after
extinction events, probably for the reason you give. But that doesn't
necessarily result in hard polytomies.
> The reason is that there is so much speciation going on after the
> extinction event there are lots of niches that are empty of
> organisms. Natural selection favors "pioneers" that explore these
> niches. If the extinction event is very short in time span, these new
> niches are all open and available at the same time. Therefore, it
> seems very likely that "hard polytomy" occurs after every short but
> intense extinction.
>
> Also, speciation isn't instantaneous. "genusiation", "familiation",
> and "orderiation" probably take much longer than "speciation". So the
> meaning of "simultaneous" is a bit ambiguous, here. There are wide
> time windows where speciation and other "radiation" can occur.
Bob Casanova
Feb 27, 2013, 1:51:27 PM2/27/13
to
On Tue, 26 Feb 2013 20:29:49 -0800, the following appeared
in talk.origins, posted by John Harshman
<jhar...@pacbell.net>:
Serious question: How does the Lake Victoria multi-species
cichlid population fit this? Is it considered to be the
result of an essentially-simultaneous multifurcation, a
rapid series of bifurcations, or something else?
ISTM that a "new" group of niches (such as Lake Victoria)
would encourage simultaneous diversification in an
introduced population; is this incorrect?
--
Bob C.
"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless
in talk.origins, posted by John Harshman
<jhar...@pacbell.net>:
cichlid population fit this? Is it considered to be the
result of an essentially-simultaneous multifurcation, a
rapid series of bifurcations, or something else?
ISTM that a "new" group of niches (such as Lake Victoria)
would encourage simultaneous diversification in an
introduced population; is this incorrect?
--
Bob C.
"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless
drose...@yahoo.com
Feb 27, 2013, 3:21:38 PM2/27/13
to
On Wednesday, February 27, 2013 11:19:24 AM UTC-5, John Harshman wrote:
That is what I meant to say. I don't know what happened to the "not". I knew that the species radiation is NOT caused by an increase in mutation rate.
My mistake. However, it still think that lots of the speciation that comes after a short-duration extinction-event is simultaneous.
I suspect that the larger taxons are not effected as much by short term extinction events. The really fundamental changes in morphology and behavior occur on a very long time scale.
Here are three separate examples with regard to the Cretaceous-paleogene (CP) extinction 65 MYA: birds, mammals and angiosperms. The class of birds and the class of flowering plants evolved during the Cretaceous and probably through a bit of the Jurassic. It took a long time for these types of organisms to develop. However, they were restricted in number and in species until the CP extinction. A few million years after the CP extinction, they were all over the place. Mammals developed during the Triassic along with the dinosaurs. However, they spread out very quickly after the CP.
No really major change occurred in the classes just because of the extinction. After the extinction event, a bird remained a bird and a flower remained a flower. Mammals continued to be mammals. The classes were unchanged. However, a few surviving species underwent relatively simple changes that enabled them to live in a vast variety of ecological niches.
The fastest change that seems to occur after an extinction event is size. Very often, what you get ten million years after an extinction event is basically the same morphology in a body that is much larger than the ancestor body before the extinction event.
Most of the birds, mammals, and flowering plants were very small before the CP extinction. During half the Paleocene, most of these animals remained small. However, toward the end of the Paleocene there were organisms much larger than their Mesozoic ancestors. The Eocene was full of gigantic mammals, birds, and flowers.
Again, this explosion is NOT due to mutation rate. I got it right this time!? This is due to empty niches becoming full.
The complex changes after the CP took tens of millions of years.
My mistake. However, it still think that lots of the speciation that comes after a short-duration extinction-event is simultaneous.
I suspect that the larger taxons are not effected as much by short term extinction events. The really fundamental changes in morphology and behavior occur on a very long time scale.
Here are three separate examples with regard to the Cretaceous-paleogene (CP) extinction 65 MYA: birds, mammals and angiosperms. The class of birds and the class of flowering plants evolved during the Cretaceous and probably through a bit of the Jurassic. It took a long time for these types of organisms to develop. However, they were restricted in number and in species until the CP extinction. A few million years after the CP extinction, they were all over the place. Mammals developed during the Triassic along with the dinosaurs. However, they spread out very quickly after the CP.
No really major change occurred in the classes just because of the extinction. After the extinction event, a bird remained a bird and a flower remained a flower. Mammals continued to be mammals. The classes were unchanged. However, a few surviving species underwent relatively simple changes that enabled them to live in a vast variety of ecological niches.
The fastest change that seems to occur after an extinction event is size. Very often, what you get ten million years after an extinction event is basically the same morphology in a body that is much larger than the ancestor body before the extinction event.
Most of the birds, mammals, and flowering plants were very small before the CP extinction. During half the Paleocene, most of these animals remained small. However, toward the end of the Paleocene there were organisms much larger than their Mesozoic ancestors. The Eocene was full of gigantic mammals, birds, and flowers.
Again, this explosion is NOT due to mutation rate. I got it right this time!? This is due to empty niches becoming full.
The complex changes after the CP took tens of millions of years.
pnyikos
Mar 1, 2013, 3:53:09 PM3/1/13
to nyi...@bellsouth.net
On Feb 25, 9:55 pm, John Harshman <jharsh...@pacbell.net> wrote:
> On 2/25/13 5:59 PM, pnyikos wrote:
>
>
>
>
>
>
>
>
>
> > On Feb 25, 6:56 pm, j...@wilkins.id.au (John S. Wilkins) wrote:
> >> John Harshman<jharsh...@pacbell.net> wrote:
> >>> On 2/25/13 3:02 PM, pnyikos wrote:
> >> ...
> >>>>>> A report in Science resolves the debate as to when the creature lived;
> >>>>>> it came about after the demise of dinosaurs.
>
> >>>>> This seems odd, considering the number of claimed Cretaceous placental
> >>>>> fossils.
>
> >>>> It also flies in the face of a huge number of estimates of divergence
> >>>> time in that website you gave me on another thread, John.
>
> >>>>http://www.timetree.org/
>
> >>> That's largely because almost all of those estimates are molecular.
> >>> There are also issues with the tree topology used (really, apparently, a
> >>> classification inferred to represent a tree).
>
> >> John, have you turned to the Dark Transformed Side?
>
> > John, would you mind putting that last comment into self-explanatory
> > English?
>
> > By the way, it seems that extant birds are also widely believed to
> > have evolved from a single common post-KT ancestor. Here is a reply
> > to me back in 2000 by Harshman's old nemesis, Cal King:
>
> However did you get from Cal King and Alan Feduccia to "widely believed"?
I didn't, turkey, the thing I posted just happened to be the concisest
> On 2/25/13 5:59 PM, pnyikos wrote:
>
>
>
>
>
>
>
>
>
> > On Feb 25, 6:56 pm, j...@wilkins.id.au (John S. Wilkins) wrote:
> >> John Harshman<jharsh...@pacbell.net> wrote:
> >>> On 2/25/13 3:02 PM, pnyikos wrote:
> >> ...
> >>>>>> A report in Science resolves the debate as to when the creature lived;
> >>>>>> it came about after the demise of dinosaurs.
>
> >>>>> This seems odd, considering the number of claimed Cretaceous placental
> >>>>> fossils.
>
> >>>> It also flies in the face of a huge number of estimates of divergence
> >>>> time in that website you gave me on another thread, John.
>
> >>>>http://www.timetree.org/
>
> >>> That's largely because almost all of those estimates are molecular.
> >>> There are also issues with the tree topology used (really, apparently, a
> >>> classification inferred to represent a tree).
>
> >> John, have you turned to the Dark Transformed Side?
>
> > John, would you mind putting that last comment into self-explanatory
> > English?
>
> > By the way, it seems that extant birds are also widely believed to
> > have evolved from a single common post-KT ancestor. Here is a reply
> > to me back in 2000 by Harshman's old nemesis, Cal King:
>
> However did you get from Cal King and Alan Feduccia to "widely believed"?
and most specific thing I've seen on the subject.
Would you like to see more? All you have to do is to go on record as
disbelieving it, and I'll oblige you.
> > Timely, eh? Harshman has been active on a thread he started, in which
> > he disses Feduccia.
> Why is it your practice to introduce anything at any time that you
> happen to think of by free association?
What could be more natural than to free associate Neornithes with
Plancentalia when there is such a juicy connection?
Could it be that you were hoping that Feduccia thread you started
would NEVER look at any specific bits of foolishness by Feduccia?
Could it be that you hadn't read the article in _Auk_ yourself, but
saw red when you saw it and dashed off a letter to the editors devoid
of any reasoned criticism?
This could easily be tested by you posting that letter. Do you have
the integrity to do that?
Peter Nyikos
pnyikos
Mar 5, 2013, 11:33:42 AM3/5/13
to nyi...@bellsouth.net
On Feb 26, 6:49�pm, j...@wilkins.id.au (John S. Wilkins) wrote:
cladists do want to resolve polytomies, and aren't satisfied until
they succeed.
> This is a virtue in a scientific discipline, I
> woul dhave thought, that it refuses to make assertions in the basence of
> evidence.
Of sufficient evidence, anyway.
This is a good description of my behavior in assessing the claims of
some people about prawnster and Giwer, and a number of others
generally held in contempt, but here in talk.origins that is widely
considered to be a vice rather than a virtue.
Peter Nyikos
> pnyikos <nyik...@bellsouth.net> wrote:
> > Since it is almost a heresy
> > among cladistic systematists to have trifurcations in a phylogenetic
> > tree, there is no cause for surprise IMHO.
>
> It's not heresy. It's a polytomy, which simply means that there is
> insufficient data to make dichotomies. It's a statement of "insufficient
> information to resolve".
I was exaggerating for effect. I believe it is fair to say that
> > Since it is almost a heresy
> > among cladistic systematists to have trifurcations in a phylogenetic
> > tree, there is no cause for surprise IMHO.
>
> It's not heresy. It's a polytomy, which simply means that there is
> insufficient data to make dichotomies. It's a statement of "insufficient
> information to resolve".
cladists do want to resolve polytomies, and aren't satisfied until
they succeed.
> This is a virtue in a scientific discipline, I
> woul dhave thought, that it refuses to make assertions in the basence of
> evidence.
This is a good description of my behavior in assessing the claims of
some people about prawnster and Giwer, and a number of others
generally held in contempt, but here in talk.origins that is widely
considered to be a vice rather than a virtue.
Peter Nyikos
Klaus Hellnick
Mar 5, 2013, 6:23:26 PM3/5/13
to
"pnyikos" wrote in message
news:ba322d5c-ff51-4e98...@y4g2000yqa.googlegroups.com...
"By the way, it seems that extant birds are also widely believed to
have evolved from a single common post-KT ancestor. Here is a reply
to me back in 2000 by Harshman's old nemesis, Cal King:"
Ducks, parrots, rattites and others already had diversified before the K-T
extinction.
This is what is widely believed.
You quote two well known crackpots, who contradict each other.
Klaus
pnyikos
Mar 6, 2013, 8:35:32 AM3/6/13
to nyi...@math.sc.edu, nyi...@bellsouth.net
On Mar 5, 6:23�pm, "Klaus Hellnick" <khelln...@sbcglobal.net> wrote:
> "pnyikos" �wrote in message
>
> news:ba322d5c-ff51-4e98...@y4g2000yqa.googlegroups.com...
>
> "By the way, it seems that extant birds are also widely believed to
> have evolved from a single common post-KT ancestor. �Here is a reply
> to me back in 2000 by Harshman's old nemesis, Cal King:"
>
> Bullshit!!!
> Ducks, parrots, rattites and others already had diversified before the K-T
> extinction.
> This is what is widely believed.
And it is also widely believed that ungulates, insectivores,
> "pnyikos" �wrote in message
>
> news:ba322d5c-ff51-4e98...@y4g2000yqa.googlegroups.com...
>
> "By the way, it seems that extant birds are also widely believed to
> have evolved from a single common post-KT ancestor. �Here is a reply
> to me back in 2000 by Harshman's old nemesis, Cal King:"
>
> Bullshit!!!
> Ducks, parrots, rattites and others already had diversified before the K-T
> extinction.
> This is what is widely believed.
Xenarthans, primates, and bats had done so as well.
Your point?
> You quote two well known crackpots, who contradict each other.
> Klaus
to the test.
Let's see whether you can do better than Harshman in dealing with the
following post of mine from last year. His reply, to put it mildly,
was underwhelming.
On Apr 26, 6:41 pm, John Harshman <jharsh...@pacbell.net> wrote:
> pnyikos wrote:
> > On Apr 26, 10:52 am, John Harshman <jharsh...@pacbell.net> wrote:
> >> pnyikos wrote:
> >>> On Apr 24, 10:41 am, John Harshman <jharsh...@pacbell.net> wrote:
> >>>> pnyikos wrote:
> >>>>> John Harshman wrote:
> >>>>>> And doubtless there would be some
> >>>>>> other term for anything more closely related to Morganucodon than to
> >>>>>> Marmota.
> >>>>> Not if ranks were abolished. How would you quantify "more closely
> >>>>> related"?
> >>>> Surely you know this if you just think about it.
>
> >>> I have known since childhood that the Linnean classification has a
> >>> way. Your suggestions below are flawed.
>
> >> You have known wrong. Arbitrary dividing lines don't do a good job even
> >> of quantifying similarity, much less relationship.
>
> > The word "arbitrary" is extremely ambiguous. Put it this way: the
> > fewer and more insignificant the apomorphies, the smaller the Linnean
> > taxon. Thus the hypothetical young digger could be quite
> > communicative ("within error bars" to use an expression familiar to
> > you) if he said, "these morganucodonts are in the same subfamily as
> > Morganucodon, whereas the examples YOU name aren't even in the same
> > infraclass."
>
> I've asked you several times for the criteria you use to assign ranks to
> taxa. No response so far. How few is few? How insignificant is
> insignificant? How small is small?
I'm sure the systematists of old had a very good feel for this kind of
thing--just from a lifelong interest in the various Linnean taxa.
It's obvious, for instance, that the shoulder girdle of the platypus
should weigh far, far more in the classification than a dozen or so
mitochondrial genes.
These were presumably what led one article to classify it in a clade
with marsupials that excluded placentals. We've talked about this
before, and you agreed we shouldn't put too much faith in such
analyses.
Where the shoulder girdle is concerned, I'm not just talking about the
disappearance in all marsupials and placentals of the interclavicle
and procoracoid, primitive features shared by the platypus,
pelycosaurs, and therapsids.
One could write that off as homoplasy. But on p. 279 of Romer's
classic _Vertebrate Paleontology_, there is a picture of four shoulder
girdles, and the scapula of the "Virginia opossum" *Didelphis* has a
shape and mid-ridge that is very much like that of all placentals that
I have ever seen, while the one for the platypus is much more similar
to that of the pelycosaur and the therapsid that is in the
reproduction.
That feature, all by itself, cries out for putting marsupials and
placentals in a clade that excludes the platypus, and it would take a
huge number of countervailing characters to overturn that assessment,
unless they happened to be as striking as the shoulder girdle
differences.
> >>>> "Sharing a more recent
> >>>> common ancestor"
> >>> That might backfire. The way the tree of life is rooted, Morganucodon
> >>> might not have a common ancestor with anything except the huge clade
> >>> in which Mormota is located, of which the genus Morganucodon is thus
> >>> the sister group.
> >> I am unable to interpret that confusing statement. Everything has a
> >> common ancestor with everything else.
>
> > Sorry, I should have added "more recent" between "might not have a"
> > and "common ancestor". It was late and I was getting sleepy.
>
> Still doesn't make sense.
Morganucodon had various common ancestors with everything else [except
maybe prokaryotes] but none of them might have been more recent than
the one it shared with all of Mammalia and most of "Mammaliforma".
Does this still not make sense to you?
[snip side issue which is sure to come up later, on a more appropriate
thread]
> >>> If what I said above is true, and Morganucodon had no descendants, the
> >>> least inclusive clade containing Morganucodon besides *Morganucodon*
> >>> itself, is the huge clade containing Eutheria, and probably
> >>> Metatheria.
> >> Better than that. Morganucodon is actually outside Mammalia as commonly
> >> defined these days (i.e. as a crown group). It's a mammaliaform. How is
> >> this a problem?
>
> > The concept of "mammaliform" could be a problem if the vexing question
> > of where monotremes belong takes yet another turn. Because then a lot
> > of "mammaliform" creatures -- essentially ALL known Jurassic mammals
> > -- could suddenly become part of Mammalia.
>
> Not a problem for me. Is it a problem for you?
No, because I keep carrying old paraphyletic groups around in my head,
and this only requires a minor adjustment for me.
> > In Romer's day, ALL Jurassic mammals then known were widely believed
> > to be in the crown group formed by the extant mammals. Romer himself
> > thought that there was good evidence that all known Jurassic mammals
> > were "more advanced" than monotremes, and hence "more closely related"
> > cladistically speaking, to placentals and marsupials.
>
> > Item: the molars of the Cretaceous monotreme *Steropodon* and even the
> > Miocene (or is it Pliocene? I forget.) platypus *Obdurodon* look more
> > like the teeth of the triconodont *Priacodon* than the molars of a
> > "pantothere" or a "symmetrodont" or those of a Metatherian or
> > Eutherian.
> > So, unless the countervailing evidence is strong, all of these
> > critters could become part of "Mammalia" from which (if Mammalia is a
> > crown group, as you say) they are currently excluded.
>
> Not a problem. Even if "look more like" is counted as a synapomorphy.
>
> > On the other hand, Morganucodon would probably continue to be
> > excluded, because the quadrate and articular bones have not yet become
> > the malleus and incus as they have in monotremes. This key change is
> > IMO the best way to define "Mammalia".
But -- stop the presses! Today I saw in Wikipedia that there is a
(controversial) theory that this changeover is a case of convergent
evolution between monotremes and other extant mammals. The references
are:
Rich, T. H.; Hopson, J. A.; Musser, A. M.; Flannery, T. F.; & Vickers-
Rich, P. (2005). "Independent origins of middle ear bones in
monotremes and therians.". Science (Science) 307 (5711): 910 -
914. doi:10.1126/science.1105717. PMID 15705848. 10.1126/science.
1105717.
^ "Comment on "Independent Origins of Middle Ear Bones in Monotremes
and Therians" (I)". Science Magazine. Retrieved 2007-10-21.
^ "Comment on "Independent Origins of Middle Ear Bones in Monotremes
and Therians" (II)". Science Magazine. Retrieved 2007-10-21.
When I get into the University, I'll see just how strong the _Science_
paywall is; if I can't see these items, I'll take a trek down to the
library, but perhaps not today.
If this theory triumphs, then the dividing line between traditional
Reptilia and Mammalia will have to be different from the one I was
using, because polyphyletic taxa were shunned by Linnean
paleontologists as much as they are by people who use
"phylogenetic" [read: cladistic] classifications.
Peter Nyikos
pnyikos
Mar 6, 2013, 12:47:48 PM3/6/13
to nyi...@bellsouth.net
On Mar 1, 4:11�pm, John Harshman <jharsh...@pacbell.net> wrote:
Actions [or, in this case, omissions] speak louder than words; you did
not satisfy the sufficient condition I gave.
It isn't a necessary condition, but unless you oblige, this theme goes
on the back burner.
And it may be due to a semantic cofusion. When I say "widely
believed" I mean "believed by either a majority or a sizable
minority." If you thought I meant only the majority bit, perhaps this
will make you lose interest in the whole issue.
> >>> Timely, eh? �Harshman has been active on a thread he started, in which
> >>> he disses Feduccia.
>
> > Methinks the Harshman doth protest too much below:
>
> >> Why is it your practice to introduce anything at any time that you
> >> happen to think of by free association?
>
> > My, my, my! �It looks like I've touched a raw nerve in you.
>
> Yes, you annoy me whenever you launch into your random digressions. Is
> that your intention?
Grotesque use of "random" noted.
Those earlier "annoyances" only touched well-protected nerves. This
one is different, but it takes a trained eye to see it. Read on.
> > What could be more natural than to free associate Neornithes with
> > Plancentalia when there is such a juicy connection?
>
> > Could it be that you were hoping that Feduccia thread you started
> > would NEVER look at any specific bits of foolishness by Feduccia?
>
> No, it couldn't be.
Then why are you only revealing your disagreement with specific
aspects here rather than there?
> > Could it be that you hadn't read the article in _Auk_ yourself, but
> > saw red when you saw it and dashed off a letter to the editors devoid
> > of any reasoned criticism?
>
> No, it couldn't be. Have you read the article? It has nothing whatsoever
> to do with Neornithes.
I see you are not averse to "random" free associations yourself. Here
we are talking about Feduccia's "sins" in your eyes and you bring in
the word "Neornithes" which NOWHERE appears above.
>
> > This could easily be tested by you posting that letter. �Do you have
> > the integrity to do that?
>
> I don't see integrity has anything to do with it. Nor do I see that you
> have any right to see a letter I wrote to another person.
I said nothing about rights, you stuck-in-the-sixties old codger.
Unless they've replied, I see no harm in making your letter to them
public.
> But I will
> repeat my reasoned criticism if you like, to the extent I can remember
> it.
++++++++++++++++++++++++ Harshman posting style on
Yes, I'd like for you to do so. Let me know when you begin.
++++++++++++++++++++++++ Harshman posting style off
See how raw that nerve was? I actually got you do do something you
adamantly refused to do in the thread that you set up for dealing with
Feduccia's article.
> If I recall, my major point was that Feduccia conflates phylogeny
> with evolutionary scenarios;
I don't see how anyone with more than 1% of his training could
possibly do so. What you say below is unrelated to this bizarre
claim.
> specifically, assumes a nonexistent,
> necessary linkage between birds as theropods, a ground-up origin of
> flight, and the absence of secondarily flightless birds in the Mesozoic.
I see that he says the lattter two are conclusions "based on" the
thesis that "birds are dinosaurs" [note, "dinosaurs," not
"theropods"], but he is attempting to characterize the thought
processes of the movers and shakers who accept that "birds are
dinosaurs" is established fact.
Strangely enough, I found that Robert T. Bakker, in his 1986 book _The
Dinosaur Heresies_, does NOT that linkage; he even praises Feduccia on
p.319 of my copy. I had been unaware of this before today, because
he only refers to Feduccia in the text as "an ornothologist [sic.]
from North Carolina" and it was only a few days ago that I learned of
Feduccia's whereabouts from the article in _The Auk_.
Anyway, Bakker says that Feduccia was partly instrumental in his re-
conversion to the then-reigning orthodoxy that *Archaeopteryx* was a
"climbing and gliding flyer".
The other big surprise this morning came when I found that he nowhere
endorses the claim that dinosaurs had feathers, despite the fact that
he did a cover article for Scientific American back in 1975 in which
one of the pictures was a drawing labeled "feathered dinosaur".
How "mainstream" is Bakker these days?
> A second point, which I have already mentioned to you, is that his story
> has changed radically, and that all the evidence formerly adduced that
> maniraptorans were unrelated to birds has disappeared now that he thinks
> maniraptorans aren't dinosaurs.
He never comes out and says that in the article, although he does hint
at it several times. Do you know of a reference where he actually
comes out and says it?
> So are you ever going to return to anything relating to the actual
> subject of Feduccia's rant?
I was way ahead of you in the original thread, and I'm way ahead of
you now, by the looks of it.
Peter Nyikos
> On 3/1/13 12:53 PM, pnyikos wrote:
> > On Feb 25, 9:55 pm, John Harshman<jharsh...@pacbell.net> �wrote:
> >> On 2/25/13 5:59 PM, pnyikos wrote:
> >>> By the way, it seems that extant birds are also widely believed to
> >>> have evolved from a single common post-KT ancestor. �Here is a reply
> >>> to me back in 2000 by Harshman's old nemesis, Cal King:
>
> >> However did you get from Cal King and Alan Feduccia to "widely believed"?
>
> > I didn't, turkey, the thing I posted just happened to be the concisest
> > and most specific thing I've seen on the subject.
>
> > Would you like to see more? �All you have to do is to go on record as
> > disbelieving it, and I'll oblige you.
>
> Yes, I would like to see the "widely believed".
> > On Feb 25, 9:55 pm, John Harshman<jharsh...@pacbell.net> �wrote:
> >> On 2/25/13 5:59 PM, pnyikos wrote:
> >>> By the way, it seems that extant birds are also widely believed to
> >>> have evolved from a single common post-KT ancestor. �Here is a reply
> >>> to me back in 2000 by Harshman's old nemesis, Cal King:
>
> >> However did you get from Cal King and Alan Feduccia to "widely believed"?
>
> > I didn't, turkey, the thing I posted just happened to be the concisest
> > and most specific thing I've seen on the subject.
>
> > Would you like to see more? �All you have to do is to go on record as
> > disbelieving it, and I'll oblige you.
>
Actions [or, in this case, omissions] speak louder than words; you did
not satisfy the sufficient condition I gave.
It isn't a necessary condition, but unless you oblige, this theme goes
on the back burner.
And it may be due to a semantic cofusion. When I say "widely
believed" I mean "believed by either a majority or a sizable
minority." If you thought I meant only the majority bit, perhaps this
will make you lose interest in the whole issue.
> >>> Timely, eh? �Harshman has been active on a thread he started, in which
> >>> he disses Feduccia.
>
> > Methinks the Harshman doth protest too much below:
>
> >> Why is it your practice to introduce anything at any time that you
> >> happen to think of by free association?
>
> > My, my, my! �It looks like I've touched a raw nerve in you.
>
> that your intention?
Grotesque use of "random" noted.
Those earlier "annoyances" only touched well-protected nerves. This
one is different, but it takes a trained eye to see it. Read on.
> > What could be more natural than to free associate Neornithes with
> > Plancentalia when there is such a juicy connection?
>
> > Could it be that you were hoping that Feduccia thread you started
> > would NEVER look at any specific bits of foolishness by Feduccia?
>
Then why are you only revealing your disagreement with specific
aspects here rather than there?
> > Could it be that you hadn't read the article in _Auk_ yourself, but
> > saw red when you saw it and dashed off a letter to the editors devoid
> > of any reasoned criticism?
>
> to do with Neornithes.
I see you are not averse to "random" free associations yourself. Here
we are talking about Feduccia's "sins" in your eyes and you bring in
the word "Neornithes" which NOWHERE appears above.
>
> > This could easily be tested by you posting that letter. �Do you have
> > the integrity to do that?
>
> have any right to see a letter I wrote to another person.
I said nothing about rights, you stuck-in-the-sixties old codger.
Unless they've replied, I see no harm in making your letter to them
public.
> But I will
> repeat my reasoned criticism if you like, to the extent I can remember
> it.
++++++++++++++++++++++++ Harshman posting style on
Yes, I'd like for you to do so. Let me know when you begin.
++++++++++++++++++++++++ Harshman posting style off
See how raw that nerve was? I actually got you do do something you
adamantly refused to do in the thread that you set up for dealing with
Feduccia's article.
> If I recall, my major point was that Feduccia conflates phylogeny
> with evolutionary scenarios;
I don't see how anyone with more than 1% of his training could
possibly do so. What you say below is unrelated to this bizarre
claim.
> specifically, assumes a nonexistent,
> necessary linkage between birds as theropods, a ground-up origin of
> flight, and the absence of secondarily flightless birds in the Mesozoic.
I see that he says the lattter two are conclusions "based on" the
thesis that "birds are dinosaurs" [note, "dinosaurs," not
"theropods"], but he is attempting to characterize the thought
processes of the movers and shakers who accept that "birds are
dinosaurs" is established fact.
Strangely enough, I found that Robert T. Bakker, in his 1986 book _The
Dinosaur Heresies_, does NOT that linkage; he even praises Feduccia on
p.319 of my copy. I had been unaware of this before today, because
he only refers to Feduccia in the text as "an ornothologist [sic.]
from North Carolina" and it was only a few days ago that I learned of
Feduccia's whereabouts from the article in _The Auk_.
Anyway, Bakker says that Feduccia was partly instrumental in his re-
conversion to the then-reigning orthodoxy that *Archaeopteryx* was a
"climbing and gliding flyer".
The other big surprise this morning came when I found that he nowhere
endorses the claim that dinosaurs had feathers, despite the fact that
he did a cover article for Scientific American back in 1975 in which
one of the pictures was a drawing labeled "feathered dinosaur".
How "mainstream" is Bakker these days?
> A second point, which I have already mentioned to you, is that his story
> has changed radically, and that all the evidence formerly adduced that
> maniraptorans were unrelated to birds has disappeared now that he thinks
> maniraptorans aren't dinosaurs.
He never comes out and says that in the article, although he does hint
at it several times. Do you know of a reference where he actually
comes out and says it?
> So are you ever going to return to anything relating to the actual
> subject of Feduccia's rant?
I was way ahead of you in the original thread, and I'm way ahead of
you now, by the looks of it.
Peter Nyikos
pnyikos
Mar 21, 2013, 4:13:13 PM3/21/13
to nyi...@bellsouth.net
Getting back to on-topic commentary, on an article of last month.
On Feb 25, 4:56�pm, pnyikos <nyik...@bellsouth.net> wrote:
> I have added sci.bio.paleontology. �This is the second post to this
> thread in talk.origins; the first had to do with a little "intramural"
> confusion exclusive to t.o.
>
> On Feb 25, 2:59 pm, pnyikos <nyik...@bellsouth.net> wrote:
>
> > In the February 8 issue of _Science_, an international team of
> > researchers published a paper that is sure to ignite a lot of
> > controversy among paleontologists and people in related fields. This
> > is because they place the last common ancestor of ALL living placental
> > mammals after the extinction of the dinosaurs.
>
> http://www.sciencemag.org/content/339/6120/662.full
>
> The full article is paywalled, but perhaps the evolutionary tree
> referenced at the end of this post is not.
>
> What is especially noteworthy is that the authors do NOT reassess the
> molecular evidence for this late date, but rely on fossil evidence
> (and perhaps some sophisticated morphological thinking in the
> supplementary article, which runs to 131 pages).
>
> And yet, the following website, also in a supplement to a _Science_
> article, claims the existence of a ca. 5-kilo condylarth and a
> taenolabid of the same size from 105.5 mya:
> http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
>
> Taenolabids may or may not be placentals
Oops, they are multituberculates. I was thinking of taenodonts.
These were omitted even from the 135 page supplement to this article
> -- they �have long been
> extinct -- but condylarths were primitive placentals related to extant
> ungulates.
>
> Even if this critter turns out to have been mis-identified, it seems
> very shaky to conclude from the dearth of clearly identifiable
> Cretaceous placental mammals that the LCA lived after the K-T
> extinction event.
As a matter of fact, the article shows quite a number of "ghost taxa"
within Placentalia, with a hypothesized separate evolution from the
rest of the tree [see url below] of decades in some cases, including
45 million for Tubulidentata.
http://www.sciencemag.org/content/339/6120/662/F1.large.jpg
So it would seem a tad inconsistent to overturn huge amounts of
molecular data on the basis of a lack of fossils, which is what this
article does.
The biggest surprise in the tree is that *Rodhocetus*, generally
accepted to be even more certainly a whale than Ambulocetus, is put
outside the whole clade of "Euungulata".
Another shortcoming of the tree is that it excludes many extinct
taxa. No "native" South American ungulate groups [nothoungulates,
litopterns, xenungulates, astrapotheres, pyrotheres] and only a few
genera; and no pantodonts, no uintatheres, no taenodonts, no
tillodonts. Very strange, considering that it was fossils, not
genomes, that were used for coming up with the tree--and the dates.
Pantodonts, uintatheres, taenodonts, and tillodonts don't even figure
in the 135 page supplement. A disappointment.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
On Feb 25, 4:56�pm, pnyikos <nyik...@bellsouth.net> wrote:
> I have added sci.bio.paleontology. �This is the second post to this
> thread in talk.origins; the first had to do with a little "intramural"
> confusion exclusive to t.o.
>
> On Feb 25, 2:59 pm, pnyikos <nyik...@bellsouth.net> wrote:
>
> > In the February 8 issue of _Science_, an international team of
> > researchers published a paper that is sure to ignite a lot of
> > controversy among paleontologists and people in related fields. This
> > is because they place the last common ancestor of ALL living placental
> > mammals after the extinction of the dinosaurs.
>
> http://www.sciencemag.org/content/339/6120/662.full
>
> The full article is paywalled, but perhaps the evolutionary tree
> referenced at the end of this post is not.
>
> What is especially noteworthy is that the authors do NOT reassess the
> molecular evidence for this late date, but rely on fossil evidence
> (and perhaps some sophisticated morphological thinking in the
> supplementary article, which runs to 131 pages).
>
> And yet, the following website, also in a supplement to a _Science_
> article, claims the existence of a ca. 5-kilo condylarth and a
> taenolabid of the same size from 105.5 mya:
> http://www.sciencemag.org/content/suppl/2010/11/22/330.6008.1216.DC1/Smith.SOM.pdf
>
> Taenolabids may or may not be placentals
These were omitted even from the 135 page supplement to this article
> -- they �have long been
> extinct -- but condylarths were primitive placentals related to extant
> ungulates.
>
> Even if this critter turns out to have been mis-identified, it seems
> very shaky to conclude from the dearth of clearly identifiable
> Cretaceous placental mammals that the LCA lived after the K-T
> extinction event.
within Placentalia, with a hypothesized separate evolution from the
rest of the tree [see url below] of decades in some cases, including
45 million for Tubulidentata.
http://www.sciencemag.org/content/339/6120/662/F1.large.jpg
So it would seem a tad inconsistent to overturn huge amounts of
molecular data on the basis of a lack of fossils, which is what this
article does.
The biggest surprise in the tree is that *Rodhocetus*, generally
accepted to be even more certainly a whale than Ambulocetus, is put
outside the whole clade of "Euungulata".
Another shortcoming of the tree is that it excludes many extinct
taxa. No "native" South American ungulate groups [nothoungulates,
litopterns, xenungulates, astrapotheres, pyrotheres] and only a few
genera; and no pantodonts, no uintatheres, no taenodonts, no
tillodonts. Very strange, considering that it was fossils, not
genomes, that were used for coming up with the tree--and the dates.
Pantodonts, uintatheres, taenodonts, and tillodonts don't even figure
in the 135 page supplement. A disappointment.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
0 new messages