Coronodon as a transitional form

[jillery]

Not to take any steam away from any other topics which might have
something to do with cladistics and transitional forms, PZ posted
another one of his weekly Youtube videos. In it, he just happens to
say some things relevant to those subjects.

<https://freethoughtblogs.com/pharyngula/2017/12/10/another-cool-fossil-coronodon/>

<https://tinyurl.com/y98tumu7>

Short version: PZ describes the teeth of a newly discovered fossil
whale. What makes the teeth especially interesting is they are
multi-cusped, similar to those of modern crabeater and leopard seals.
This suggests that coronodon used them in a similar way, to filter
small animals from mouthfuls of water prior to swallowing them.

What makes coronodon a transitional form is not its teeth per se, but
its likely feeding behavior suggested by its teeth. Modern toothed
whales are raptorial feeders, where they grab individual prey.
Coronodon could do that also, but that method doesn't work well with
small animals like krill. For those cases, Coronodon likely used its
teeth like some modern whales use baleen, to grab or suck a mouthful
of plankton-filled water, and then squeeze out the water with its
tongue and lick off the prey trapped between its teeth.

PZ makes the point that transitional species aren't necessarily
directly ancestral to or descended from any other whale species, but
only that they share a close evolutionary relationship. There almost
certainly were other species which fed similarly, and any one of those
would have found actual baleen worked much better than even
multi-cusped teeth.

For those who wish to view the video directly:

<https://youtu.be/do-mTthULrY>

For those interested in reading more about it:

<https://www.sciencedaily.com/releases/2017/06/170629143018.htm>

<http://www.cell.com/current-biology/fulltext/S0960-9822(17)30704-2>

The link says it's to fulltext, but it's only to the abstract.



--
I disapprove of what you say, but I will defend to the death your right to say it.

Evelyn Beatrice Hall
Attributed to Voltaire

[J.LyonLayden]

Great articles and video thank you. I would like to point out this is true, but it works both ways. Modern whales may not have evolved directly from Himalayacetus, Basilosaurus, or coronodon...all of which have heterodont teeth like most mammals. But modern whales have homodont teeth, so a sister species is implied and the teeth are to have become homodont over time.

But Xenarthra, most "basal" of mammals, has homodont teeth. Maybe the whales we have fossils of were specialized, since heterodont is evidence of adaptation at least to some degree. Maybe the homodont whales of the early paleogene were homodonts just like modern whales and early mammals; they just lived deep in the ocean where no fossils are preserved.

[Ernest Major]

If you do a parsimony analysis you'll find that heterdonty is primitive
in mammals (and a more inclusive clade) and homodonty is derived.

It's questionable whether Xenarthra is "basal" in placentals, never mind
more inclusive groups: there is support for the Atlantogeneta, Epitheria
and Exafroplacentalia hypothesis. It's also questionable whether
Xenartha is primitively homodont; sloths for example have both
caniniform and molariform teeth.

Basal whales (raoellids, pakicetids and ambulocetids) were heterodont.

You seem to be assuming a character state polarity and postulating
multiple ghost lineages to make the trait fit the phylogeny.

--
alias Ernest Major

[Ernest Major]

Note that described character states as primitive and advanced is
problematical - it leads people astray into thinking of evolution as a
unidirectional process from simple to complex forms, while in actuality
any bias is small, and the evolution of simplicity is found commonly
(e.g. there are a considerably number of secondarily simplified
parasitic crustaceans, e.g. there are several different lineages of
achlorophyllous parasitic plants). Describing character states as
ancestral and derived is less likely to lead one astray.

--
alias Ernest Major

[jillery]

Personally, I associate "primitive" and "advanced" as referring to a
character's chronological appearance, and not its relative complexity.
I suppose for some people "ancestral" and "derived" better imply
chronology, but have the disadvantage of more strongly implying a
lineal evolutionary relationship, which is an implication cladistics
tries to avoid. So I don't see either set of labels as better or
worse, but merely differently insufficient.

The fundamental problem is it's usually not possible to say with any
reasonable certainty which feature or which species is directly
ancestral to, or derived from, any other feature or species. Perhaps
using a phrase like "ancestral candidate" more accurately identifies
that uncertainty, at the expense of being more grammatically
cumbersome.

[jillery]

>> For those who wish to view the video directly:
>>
>> <https://youtu.be/do-mTthULrY>
>>
>> For those interested in reading more about it:
>>
>> <https://www.sciencedaily.com/releases/2017/06/170629143018.htm>
>>
>> <http://www.cell.com/current-biology/fulltext/S0960-9822(17)30704-2>
>>
>> The link says it's to fulltext, but it's only to the abstract.
>
>
>Great articles and video thank you. I would like to point out this is true, but it works both ways. Modern whales may not have evolved directly from Himalayacetus, Basilosaurus, or coronodon...all of which have heterodont teeth like most mammals. But modern whales have homodont teeth, so a sister species is implied and the teeth are to have become homodont over time.
>
>But Xenarthra, most "basal" of mammals, has homodont teeth. Maybe the whales we have fossils of were specialized, since heterodont is evidence of adaptation at least to some degree. Maybe the homodont whales of the early paleogene were homodonts just like modern whales and early mammals; they just lived deep in the ocean where no fossils are preserved.

AIUI cladistics rightly attempts to avoid making conclusions about
direct evolutionary relationships of fossil species. So it's unlikely
you will find anybody who authoritatively identifies any fossil
species as being directly ancestral to modern whales, their teeth
notwithstanding.

Some might view this as a weakness of cladistics, but I see it as
accepting a necessary reality, that fossils almost never preserve
enough detail to support such conclusions. Instead, cladistics
attempts to identify the relative evolutionary distances of fossil
species to each other and to extant species.

Whales with baleen (mysticetes) almost certainly descended from
toothed whales (odontocetes). All mysticetes are almost certainly
more closely related to each other than they are to odontocetes.
Species like coronodon, which had no baleen but almost certainly ate
like one, are an important transitional form between these major whale
groups.

[John Harshman]

That's correct, if you mean "order of appearance on a phylogenetic tree"
rather than "order of appearance in the fossil record". Relative
complexity is irrelevant, which is what Ernest was saying.

I like "primitive" and "derived" myself, where "primitive" just means
"present in the ancestor".

> I suppose for some people "ancestral" and "derived" better imply
> chronology, but have the disadvantage of more strongly implying a
> lineal evolutionary relationship, which is an implication cladistics
> tries to avoid. So I don't see either set of labels as better or
> worse, but merely differently insufficient.
>
> The fundamental problem is it's usually not possible to say with any
> reasonable certainty which feature or which species is directly
> ancestral to, or derived from, any other feature or species. Perhaps
> using a phrase like "ancestral candidate" more accurately identifies
> that uncertainty, at the expense of being more grammatically
> cumbersome.

Here I would disagree. We can say that features are ancestral, meaning
"the condition present in the ancestor", even though we can't identify
the ancestor with any actual fossil. Like anything in science, the
inference can't be "proved", but it can be close enough for all
practical purposes.

[Ernest Major]

We could always go full jargon with plesiomorphic and apomorphic.

>
>> I suppose for some people "ancestral" and "derived" better imply
>> chronology, but have the disadvantage of more strongly implying a
>> lineal evolutionary relationship, which is an implication cladistics
>> tries to avoid.  So I don't see either set of labels as better or
>> worse, but merely differently insufficient.
>>
>> The fundamental problem is it's usually not possible to say with any
>> reasonable certainty which feature or which species is directly
>> ancestral to, or derived from, any other feature or species.  Perhaps
>> using a phrase like "ancestral candidate" more accurately identifies
>> that uncertainty, at the expense of being more grammatically
>> cumbersome.
>
> Here I would disagree. We can say that features are ancestral, meaning
> "the condition present in the ancestor", even though we can't identify
> the ancestor with any actual fossil. Like anything in science, the
> inference can't be "proved", but it can be close enough for all
> practical purposes.
>

--
alias Ernest Major

[J.LyonLayden]

So they think a gene evolved in Cingulata 56 million years ago that prevents heterodont specialization? Did a different gene to prevent heterodonty develop in the homodont sloths?

And then another gene evolved in later whales to prevent heterodont dentition too? Do they think it happened individually in whales or from a common ancestor? And why would it require any more than one ghost lineage for whales?

Thanks.

[jillery]

Since the fossil record is notoriously incomplete, there's no way to
know if fossils represent the actual order characters appeared in real
life. This is similar to the problem of claiming a particular fossil
species is ancestral to, or descended from, another fossil species.

>I like "primitive" and "derived" myself, where "primitive" just means
>"present in the ancestor".

Scientists use words and phrases to mean different things than are
meant by the general population, or even other scientists. If
astronomers can get away with calling all elements but hydrogen and
helium "metals", contrary to even the definition of chemists, then
paleontologists shouldn't have to worry about the word games
pseudo-skeptics like to play with their choice of words.

>> I suppose for some people "ancestral" and "derived" better imply
>> chronology, but have the disadvantage of more strongly implying a
>> lineal evolutionary relationship, which is an implication cladistics
>> tries to avoid. So I don't see either set of labels as better or
>> worse, but merely differently insufficient.
>>
>> The fundamental problem is it's usually not possible to say with any
>> reasonable certainty which feature or which species is directly
>> ancestral to, or derived from, any other feature or species. Perhaps
>> using a phrase like "ancestral candidate" more accurately identifies
>> that uncertainty, at the expense of being more grammatically
>> cumbersome.
>
>Here I would disagree. We can say that features are ancestral, meaning
>"the condition present in the ancestor", even though we can't identify
>the ancestor with any actual fossil. Like anything in science, the
>inference can't be "proved", but it can be close enough for all
>practical purposes.

ISTM if you can conclude which features are ancestral, then you should
also be able to conclude which fossil species are ancestral based on
those ancestral features. What am I missing?

[John Harshman]

Actually, there is a way to determine, or at least estimate the order:
by mapping characters onto a phylogenetic tree.

>> I like "primitive" and "derived" myself, where "primitive" just means
>> "present in the ancestor".
>
> Scientists use words and phrases to mean different things than are
> meant by the general population, or even other scientists. If
> astronomers can get away with calling all elements but hydrogen and
> helium "metals", contrary to even the definition of chemists, then
> paleontologists shouldn't have to worry about the word games
> pseudo-skeptics like to play with their choice of words.

I agree.

>>> I suppose for some people "ancestral" and "derived" better imply
>>> chronology, but have the disadvantage of more strongly implying a
>>> lineal evolutionary relationship, which is an implication cladistics
>>> tries to avoid. So I don't see either set of labels as better or
>>> worse, but merely differently insufficient.
>>>
>>> The fundamental problem is it's usually not possible to say with any
>>> reasonable certainty which feature or which species is directly
>>> ancestral to, or derived from, any other feature or species. Perhaps
>>> using a phrase like "ancestral candidate" more accurately identifies
>>> that uncertainty, at the expense of being more grammatically
>>> cumbersome.
>>
>> Here I would disagree. We can say that features are ancestral, meaning
>> "the condition present in the ancestor", even though we can't identify
>> the ancestor with any actual fossil. Like anything in science, the
>> inference can't be "proved", but it can be close enough for all
>> practical purposes.
>
> ISTM if you can conclude which features are ancestral, then you should
> also be able to conclude which fossil species are ancestral based on
> those ancestral features. What am I missing?

There are two main problems with this. First, species may not be
distinguishable by readily fossilized characters, much less those
present in often fragmentary fossils. It may be impossible to
distinguish the ancestral species from some fairly close relative.
Second, reversals do occur, so the real common ancestor may have what
looks like an autapomorphy.

And of course given the gappy nature of the record, and the ratio of
known species to those that have existed, it's unlikely that we have
found any particular ancestor.

[Ernest Major]

I doubt that they think that. Especially as the extinct armadillo genus
Macroeuphractus was heterodont. Also, what homodont sloths? (So far all
the sloths I've found details on have caniniform and molariform teeth.)

On a broad scale, and considering a single trait, heterodonty and
homodonty are equally parsimonious as the ancestral state in Xenartha:
heterodonty requires a transition to homodonty in Cingulata and
Vermilingua, and homodonty requires a transition to homodonty in
Xenartha (heterodonty goes way back in mammalian ancestry: a short
browse up the phylogenetic tree at WikiPedia suggests that it's an
apomorphy of Theriodonta) and a reversion to heterodonty in Folivora.
Macroeuphractus has derived heterodonty either way.

In the absence of any stem-Xenarthrans (at least Google isn't finding
any for me) we're stuck we examining tooth development and anatomy to
resolve the issue. On the one hand the Tetrapod Zoology blog writes
"some evidence suggests that the upper caniniform in Choloepus is a true
canine". On the other hand Xenarthra as a whole has a number of derived
dental characters (e.g. monophyodonty versus diphyodonty) so one is led
to a suspicion of a restructuring on dental anatomy on the Xenarthran
stem, with homodonty as part of the suite. On the gripping hand a paper
in Scientific Reports (https://www.nature.com/articles/srep27763 - not
paywalled) says that Bradypus has vestigal incisors as juveniles, from
which one infers that Xenarthrans had heterodont ancestors.

[There may be a usage question with regards to whether adult sloths are
heterodont - if the caniniform teeth are modified molars than under at
least some usages sloths are still homodont.]

I expect that mammalian palaeontologists and neontologists think that
dental anatomy is under the control of multiple genes, and the degree of
differentiation of teeth can change of time.

>
> And then another gene evolved in later whales to prevent heterodont dentition too? Do they think it happened individually in whales or from a common ancestor? And why would it require any more than one ghost lineage for whales?

You seem to be postulating a model of evolution in which transitions
only occur from an unspecialised homodont dentition to a specialised
heterodont dentition. That's not a problem considering Xenartha in
isolation. But if you assume that whales are primitively homodont (and
that all their ancestors were) you require the independent development
of heterodonty in Mysticeti, in various stem-Cetacean groups, in
Hippopotamidae/Anthracotheridae, in Ruminantia, in Suina, in Tylopoda,
in Perissodactyla and Carnivora (or Pegasoferae), in Meridioungulata, in
Lipotyphla, in Euarchontoglires, in Afrotheria, and so one down the
mammalian stem, with the existence of undiscovered homodont stem-taxa
for all these groups (ghost lineages). This is massively unparsimonious.

It's easier to lose a complex trait (such as the archetypal mammalian
heterodonty with distinct incisors, canines, premolars and molars) than
to evolve it. If a species adopts a lifestyle that isn't benefited by
the possession of differentiated teeth it will tend to lose the
differentiation (quickly through selection, or slowly through drift,
depending on whether they're an active handicap); if a species adopts a
lifestyle that isn't benefited by the possession of teeth it will
similarly tend to lose or simplify them.

As I understand an array of conical teeth is advantageous for catching
fish, and so animals that specialise in fish-eating will tend towards
homodonty.

Similarly animals whose prey doesn't require mastication will tend to
lose or simplify teeth. Thus this is part of the suite of characters
independently developed by anteaters (anteaters sensu strictu,
pangolins, aardvarks, numbats, echidnas). Similarly the suction-feeding,
squid-eating beaked whales have reduced dentitions.
>
> Thanks.
>


--
alias Ernest Major

[J.LyonLayden]

Everything you've written makes excellent sense and I appreciate your taking the time to write it. I understand why this is unparsimonious. However, I'm toying with the idea that most species had to undergo niche adaptation extremely quickly during the Late Cretaceous and directly following the KPg.

My tentative hypothesis is that a generalist omnivore with an osteoderm who could swim, climb, run, or close up in a ball like some 'basal" Xenarthrans would have little need to adapt into a niche. However, anything which had moved away from "generalist" and "lost" its osteoderm would need to adapt into a new niche quickly or perish. Hence turtles, crocodiles, and armadillo-like mammals survived the Cretaceous/Paleogene extinctions and niche adaptation began again.

[J.LyonLayden]

I'm assuming that the stem-taxa aren't identified anyway, and that initial placental divergence happened by the long-fuse model (73-114 million years ago).
It was my understanding that the cetacean lineage within Artiodactyla is disputed. Isn't there a camp that has its divergence near the root of Artiodactyla?

All of the others would indeed need to specialize, but I'd read that heterodonty is evidence of adaptation to a niche and environment, at least to some degree. There are a number of specialized dinosaurs with heterodont teeth, for instance.
I'm assuming less need for dinosaurs to fulfill a niche, and more need for mammals to do so during and directly after the Late Cretaceous.

I'm also supposing that a transition from heterodonty to homodonty is less likely than the reverse, though this is just a supposition.

[christi...@brown.edu]

"However, anything which had moved away from "generalist" and "lost" its osteoderm would need to adapt into a new niche quickly or perish. Hence turtles, crocodiles, and armadillo-like mammals survived the Cretaceous/Paleogene extinctions and niche adaptation began again. "

You are mistaking the notion of a basally branching form (Xenarthrans) being the same as the basal node from which they branched.

There is zero evidence that the basal form of placental was anything like an armadillo (both fossil and phylogenetic evidence strongly contradicts this).

A similar mistake type of reasoning would lead to the following conclusions:

Ratites are basal birds. Ergo, the ancestor of modern birds was a large, flightless form like an ostrich.

Camels are basal artiodactyls. Ergo pigs must have come from an ancestry of something that had two toes and a hump, and have regained the four-toed condition.

Tarsiers are basal haplorrhines. Ergo our ancestor must have had eyes bigger than its brain and elongated astragalar and calcaneal bones in the ankle.

Coelacanths are basal sarcopterygians. Ergo tetrapods must have started off with a fat-filled lung with ossified walls.

Lampreys are basal vertebrates. Thus all other vertebrates must have evolved their jaws from a sucker-like mouth with keratinous teeth.

Echinoderms are basal deuterostomes. Hence we must have evolved our bilateral symmetry from a radial symmetry, and have lost our calcified exoskeleton.

And so on and so forth.

[J.LyonLayden]

This is true and I do understand. However, the difference I see is that I have a reason for my assumption with Xenarthra. It would solve many things I find puzzling. Cingulata has retained the same basic morphology for 56 million years and hasn't lost its osteoderm. Osteoderms are complex, fight infection, allow survival in any environment. I would expect a tank to best survive a nuclear winter and a starving world. And armadillos swim between continents even today. I have more reasons, but I'd have to go back and look.

But how would I test the possibility? I am currently learning about building phylogenetic trees and parsimony analysis, thanks to John.

[J.LyonLayden]

On Wednesday, December 13, 2017 at 6:25:02 PM UTC-5, christi...@brown.edu wrote:

Allow me to ask you this for the sake of my science fiction stories. If we were to find a Doedicurus (or primitive Xenarthran) fossil in Antarctica or Mauritia which predated the KPg event, what traits would it need to have in order for us to consider it as a possible stem-mammal and LCA of placentals?

[J.LyonLayden]

I just remembered another big reason- Multituberculta were originally thought to be Xenarthrans and Gondwanathres share traits with Xenarthrans, therefore I supposed that these traits at least might have been present previously to placentals.

[John Harshman]

If we found a stem-placental, it wouldn't be a xenarthran. But the
question you ask, stripped of the xenarthran baggage, has been answered
in a paper I have already cited for you at least once: O'Leary et al.
2013. The Placental Mammal Ancestor and the Post–K-Pg Radiation of
Placentals. Science 339:662-667.

[John Harshman]

On 12/13/17 3:17 PM, J.LyonLayden wrote:
> I'm assuming that the stem-taxa aren't identified anyway, and that
> initial placental divergence happened by the long-fuse model (73-114
> million years ago).

That isn't relevant to phylogeny.

> It was my understanding that the cetacean lineage within Artiodactyla
> is disputed. Isn't there a camp that has its divergence near the root
> of Artiodactyla?

Not that I'm aware of. These days it's almost universally agreed that
the living sister group of whales is hippos, for very good reasons.

> All of the others would indeed need to specialize, but I'd read that
> heterodonty is evidence of adaptation to a niche and environment, at
> least to some degree. There are a number of specialized dinosaurs
> with heterodont teeth, for instance.

Yes, and the heterodont teeth of mammals are clearly adaptations. But
that happened in late cynodonts, before there were placentals or even
mammals. Heterodont teeth are primitive for placentals, and homodont
teeth are derived. There is no question of this.

> I'm assuming less need for dinosaurs to fulfill a niche, and more
> need for mammals to do so during and directly after the Late
> Cretaceous.

What do you mean by that, and what is its significance?

> I'm also supposing that a transition from heterodonty to homodonty is
> less likely than the reverse, though this is just a supposition.

It would have to be exceedingly less likely, by a factor of a hundred or
so in order for your scenario to work. Is your supposition strong enough
for that?

[J.LyonLayden]

Yes I like that paper and will reread it to find the description. However, it's telling us what the mammal would look like if the radiation took place post-KPg isn't it?

This paper fits continental drift much better and is a more recent paper:

Genetic Evidence Reveals Placental Mammal Radiation Uninterrupted by the KPg Boundary 2017
https://pdfs.semanticscholar.org/dbc3/a416c3c24eea1d2455b65eb479c20a6b3ea5.pdf


And you've got to admit that if mammals that diverged BEFORE placentals even arose can be mistaken as Xenarthran for decades, then it's quite confusing why a stem-mammal couldn't be Xenarthran-like.

"For several decades the affinities of the group were not clear, being first interpreted as early xenarthrans, or "toothless" mammals similar to the modern anteater." Gondwanatheres (70 mya to 15 mya)

And if you go with the Epitheria hypothesis, what is separating the stem-group from Xenarthra? It's only branching from the stem group is the same that separates it from all other placentals.

Is there a specific trait or set of traits separating it from the stem-group? Or just the fork on the tree?


Trust me there's no science fiction story in the documentary version of evolution we've been watching on Nat Geo for 35 years.


(Last sentence was a bit of humor not meant to offend)

[J.LyonLayden]

On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:
> On 12/13/17 3:17 PM, J.LyonLayden wrote:
> > I'm assuming that the stem-taxa aren't identified anyway, and that
> > initial placental divergence happened by the long-fuse model (73-114
> > million years ago).
>
> That isn't relevant to phylogeny.
>
> > It was my understanding that the cetacean lineage within Artiodactyla
> > is disputed. Isn't there a camp that has its divergence near the root
> > of Artiodactyla?
>
> Not that I'm aware of. These days it's almost universally agreed that
> the living sister group of whales is hippos, for very good reasons.
>
> > All of the others would indeed need to specialize, but I'd read that
> > heterodonty is evidence of adaptation to a niche and environment, at
> > least to some degree. There are a number of specialized dinosaurs
> > with heterodont teeth, for instance.
>
> Yes, and the heterodont teeth of mammals are clearly adaptations. But
> that happened in late cynodonts, before there were placentals or even
> mammals. Heterodont teeth are primitive for placentals, and homodont
> teeth are derived. There is no question of this.
>
> > I'm assuming less need for dinosaurs to fulfill a niche, and more
> > need for mammals to do so during and directly after the Late
> > Cretaceous.
>
> What do you mean by that, and what is its significance?

I don't see why a big giant thing would need differentiation of teeth. I don't see why a dinosaur or a massive whale would need differentiation of teeth. The same teeth will pulverize anything. Why would it need differentiation?


But plants can't photosynthesize in darkness. Therefore directly after KPg a lot of things had to MASSIVELY adapt in order to even survive. This would be the time I would expect most animals to become heterodont UNLESS they were king of the sea(whales) or the best generalist that has ever lived (Xenarthran).

A doedicurus will not give two flips about a shark trying to eat it from underneath, while any other mammal is going to get chomped swimming or rafting hundreds of miles across open ocean. An armadillo can get away from any predator. Nothing is able to eat it. Some of the most primitive species roll into a ball like pangolins. Have you ever seen a pride of lions trying to eat a pangolin? Doesn't work.


And they can hold their breath longer than any other mammal besides whales.


It can go anywhere, eat anything. Why would it need to change unless it gave up its general traits in order to exploit a niche?

[J.LyonLayden]

On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:

> On 12/13/17 3:17 PM, J.LyonLayden wrote:
> > I'm assuming that the stem-taxa aren't identified anyway, and that
> > initial placental divergence happened by the long-fuse model (73-114
> > million years ago).
>
> That isn't relevant to phylogeny.

Ok great I'm not there yet in my study. So no matter when the stem-mammal lived, the description is going to be the same as on this paper, right?

And they won't let me have an osteoderm, because they don't believe you have to lose an osteoderm to specialize. And because they don't see any evidence for a former osteoderm in placentals. Is that also right?

I think an osteoderm in the LCA would explain a great many things, so I would like to use their description and add an osteoderm. Am I not allowed to do that?

Am I not allowed to hypothesize the existence of an osteoderm?

Again, nothing negative here, I just want to be able to do this correctly. And I'm just gathering info here, I don't know how to do the tree or analysis yet. Still reading.

[J.LyonLayden]

On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:

May I allow it an osteoderm for my hypothesis and check my results if I stop calling it Xenarthra?

[erik simpson]

On Wednesday, December 13, 2017 at 8:55:02 PM UTC-8, J.LyonLayden wrote:
> On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:
>
>
>
> May I allow it an osteoderm for my hypothesis and check my results if I stop calling it Xenarthra?

Of course not. The character matrix you use to evaluate tree hypotheses has to be
honest. Fossils show what they show (not enough, usually), but you can't add
anything to them.

[J.LyonLayden]

Good grief. Ok. How do you make any kind of hypothesis that might explain a culmination of problems? Like Darwin was allowed to do?

How can I be allowed to make a hypothesis which might fill the "god of the gaps?"

[J.LyonLayden]

If there were an osteoderm in the first placental, I don't see how anything could specialize if it kept it, so I don't know why we'd expect to find one in a lot of lineages. You definitely need to lose it to remain in the Northern Hemi during the Paleogene, hence no animals with osteoderms live in the northern hemisphere. It must be too cold for them there. Full body fur must be better for survival in the cold. Exposed bone doesn't like cold.

If you have to live in a tree, that osteoderm will wear you down. Fully bipedal? Better lose that osteoderm. Living in nooks and crannies? Better lose that osteoderm. Trying to swim really fast? Better lose that osteoderm. Trying to catch other mammals? Better lose that osteoderm.


Problem is, when the bad times come, like the KPg....you aint got no osteoderm.

[John Harshman]

No. Timing is not relevant.

> This paper fits continental drift much better and is a more recent paper:
>
> Genetic Evidence Reveals Placental Mammal Radiation Uninterrupted by the KPg Boundary 2017
> https://pdfs.semanticscholar.org/dbc3/a416c3c24eea1d2455b65eb479c20a6b3ea5.pdf

Nice, but it's irrelevant to the question you claimed to be asking,
which was about the nature of the placental ancestor. Whether that
ancestor is before or after the K-T extinction doesn't affect the
reconstruction.

> And you've got to admit that if mammals that diverged BEFORE
> placentals even arose can be mistaken as Xenarthran for decades, then
> it's quite confusing why a stem-mammal couldn't be Xenarthran-like.

No, I don't have to admit that. I suggest you learn more about
phylogenetic methods before making any further such claims.

> "For several decades the affinities of the group were not clear,
> being first interpreted as early xenarthrans, or "toothless" mammals
> similar to the modern anteater." Gondwanatheres (70 mya to 15 mya)

> And if you go with the Epitheria hypothesis, what is separating the
> stem-group from Xenarthra? It's only branching from the stem group is
> the same that separates it from all other placentals.

Don't you remember anything Christine said about "basal" taxa?

> Is there a specific trait or set of traits separating it from the
> stem-group? Or just the fork on the tree?

Osteoderms would be one of those traits, wouldn't it?

> Trust me there's no science fiction story in the documentary version
> of evolution we've been watching on Nat Geo for 35 years.
> (Last sentence was a bit of humor not meant to offend)

That's OK. I didn't understand what you were trying to say anyway.

[John Harshman]

You are letting your fevered imagination carry you into fantasy with no
foundation in fact or even logic. How long do you think this "darkness"
and lack of photosynthesis would have lasted? How fast do you think
evolution can work? And you have forgotten that heterodonty originated
in therapsids long before mammals, much less placentals, even existed.

Armadillos were not rocketed to earth as infants when the distant planet
of Krypton exploded.

[J.LyonLayden]

OK cool I realized that from your other reply.

>
> > This paper fits continental drift much better and is a more recent paper:
> >
> > Genetic Evidence Reveals Placental Mammal Radiation Uninterrupted by the KPg Boundary 2017
> > https://pdfs.semanticscholar.org/dbc3/a416c3c24eea1d2455b65eb479c20a6b3ea5.pdf
>
> Nice, but it's irrelevant to the question you claimed to be asking,
> which was about the nature of the placental ancestor. Whether that
> ancestor is before or after the K-T extinction doesn't affect the
> reconstruction.
>
> > And you've got to admit that if mammals that diverged BEFORE
> > placentals even arose can be mistaken as Xenarthran for decades, then
> > it's quite confusing why a stem-mammal couldn't be Xenarthran-like.
>
> No, I don't have to admit that. I suggest you learn more about
> phylogenetic methods before making any further such claims.
>
> > "For several decades the affinities of the group were not clear,
> > being first interpreted as early xenarthrans, or "toothless" mammals
> > similar to the modern anteater." Gondwanatheres (70 mya to 15 mya)
>
> > And if you go with the Epitheria hypothesis, what is separating the
> > stem-group from Xenarthra? It's only branching from the stem group is
> > the same that separates it from all other placentals.
>
> Don't you remember anything Christine said about "basal" taxa?

I do. But camels don't have camel-looking things before placentals. Gondwanatheres don't look like camels they look like Xenarthrans.

So if something directly before LCA placental looked like a Xenarthran(Gondwanatheres), and something that branched off right after LCA placental looked like Xenarthran(Xenarthra) then it stands to reason that the thing that came between the two would also look like a Xenarthran.


Maybe the universe has different rules for paleontology in specific.

Maybe I can't make assumptions in paleontology that are elementary in every other task of logic.


I'm sorry. I was hoping to get answers from Christi since I had already gotten your opinion. Maybe I have to go to reddit to ask my questions in peace.

[John Harshman]

On 12/13/17 8:44 PM, J.LyonLayden wrote:
> On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:
>> On 12/13/17 3:17 PM, J.LyonLayden wrote:
>>> I'm assuming that the stem-taxa aren't identified anyway, and that
>>> initial placental divergence happened by the long-fuse model (73-114
>>> million years ago).
>>
>> That isn't relevant to phylogeny.
>
> Ok great I'm not there yet in my study. So no matter when the
> stem-mammal lived, the description is going to be the same as on this
> paper, right?

Right. And you need to differentiate between "mammal" and "placental" too.

> And they won't let me have an osteoderm, because they don't believe
> you have to lose an osteoderm to specialize. And because they don't
> see any evidence for a former osteoderm in placentals. Is that also
> right?

It's not even wrong. It's just gibberish.

> I think an osteoderm in the LCA would explain a great many things, so
> I would like to use their description and add an osteoderm. Am I not
> allowed to do that?

> Am I not allowed to hypothesize the existence of an osteoderm?

You can do whatever you want; it just won't make any sense, if sense is
what you're going for.

> Again, nothing negative here, I just want to be able to do this
> correctly. And I'm just gathering info here, I don't know how to do
> the tree or analysis yet. Still reading.

Keep reading.

[John Harshman]

It's hard to tell what you're even trying to say above. Once again I ask
you to pay more attention when typing and reread for clarity before posting.

[John Harshman]

Maybe you should continue reading about how phylogenetic analysis works
instead of using disconnected facts as a framework for your dreams. That
was the least sincere apology I have seen in a while.

[J.LyonLayden]

Yes and there are two ways in which osteoderms could separate it: it was either lost or it was gained.

[J.LyonLayden]

I was just asking a few questions while the topic was up. Having a nice exchange with Ernest. Christine responded to me, and I had questions in reply. I'll get back to the reading, I promise.
Sheesh.

[jillery]

On Wed, 13 Dec 2017 13:30:40 -0800, John Harshman

You seem to be backpedaling, that the fossil record *can* show the
order of appearance of characters, which would moot your previous
objection. Please clarify.

Are there no cases where fossils aren't distinguishable by character?
If not, what's wrong with recognizing those cases?

>It may be impossible to
>distinguish the ancestral species from some fairly close relative.

Same question as above. If there are cases where it's possible to
distinguish close relatives, what's wrong with recognizing them?

>Second, reversals do occur, so the real common ancestor may have what
>looks like an autapomorphy.

I had to look up "autapomorphy", but I still don't understand your
point. Please clarify.

>And of course given the gappy nature of the record, and the ratio of
>known species to those that have existed, it's unlikely that we have
>found any particular ancestor.

--
I disapprove of what you say, but I will defend to the death your right to say it.

Evelyn Beatrice Hall
Attributed to Voltaire

[Ernest Major]

You might want to revisit your belief that gondwanatheres look like
xenarthrans. Gondwanatheres was known from fragmentary fossils, and
possibly no-one knew what they looked like. The description of the
better preserved Vintana in 2004 apparently places them solidly within
or sister to Multituberculata. (The article - at
https://www.nature.com/articles/nature13922 - is paywalled.)

>
>
> Maybe the universe has different rules for paleontology in specific.
>
> Maybe I can't make assumptions in paleontology that are elementary in every other task of logic.
>
>
> I'm sorry. I was hoping to get answers from Christi since I had already gotten your opinion. Maybe I have to go to reddit to ask my questions in peace.
>
>

--
alias Ernest Major

[John Harshman]

I wasn't backpedaling.

The order of appearance in the fossil record can't show the order of
appearance in time, but a phylogenetic tree using fossils, which doesn't
incorporate any stratigraphic ordering, can show that order. The state
on a particular branch is earlier in time than a state on any descendant
branch.

Of course there are cases where fossils aren't distinguishable by
character. That's exactly what I said. But I don't see how that allows
us to call them ancestral. Explain.

>> It may be impossible to
>> distinguish the ancestral species from some fairly close relative.
>
> Same question as above. If there are cases where it's possible to
> distinguish close relatives, what's wrong with recognizing them?

We recognize them, but we can't say that either of them is ancestral to
anything.

>> Second, reversals do occur, so the real common ancestor may have what
>> looks like an autapomorphy.
>
> I had to look up "autapomorphy", but I still don't understand your
> point. Please clarify.

What we expect of an ancestral species is that it will be exactly the
same as a reconstructed ancestor, i.e. having 100% primitive character
states. But if a character present in the ancestor is reversed (going
from the derived back to the primitive state), it will look as if the
ancestral fossil has an autapomorphy, removing it from the direct line
of descent.

[J.LyonLayden]

Yes Gondwanatheres are not the only Multituberculates that have been misidentified as Xenarthrans, and Vintani has been described as Xenarthran-like as well. Vintani and Gondwanatheres have a very specific "cheek flange" that is only present in Xenarthra.

But I should not have answered that... here comes John Harshman to bully me because asking questions and replying to others is bad.

The answers I just got from Christine and John don't make much sense to me when the facts about Gondwanatheres , Vintani, and other Multituberculata are added to the data bank. Multituberculates are the closest things we have to placentals in the Late Cretaceous other than a few sporadic, highly specialized, unrelated eutherian anomalies which definitely aren't placentals and are not the LCA.

If almost everything in the Cretaceous closely related to placentals is Xenarthran-like, and Xenarthrans branched off from placentals first, then what they are saying makes little sense to me. I need more explanation. I didn't know needing more info was a bad thing.

There is one grouping that puts Xenarthrans, Marsupials, and Monotremes in a group together outside of placentals for chrissakes!

How can the LCA of placentals have become unlike Xenarthra and then like Xenarthra in only 10 million years which happen to be the 10 million years when almost nothing left any fossils?

Why are they proposing extreme saltation away from Xenarthra-like and then back into Xenarthra-like despite the lack of fossil evidence right after KPg?


The only real eutherian they have is 160 million years old and highly specialized.
Gondwanatheres are 70 mya. Vintani is 66.5 mya. Doedicuris if 56.5 mya.


When did the sister taxa of Multituberculates that led to placentals have time to rapidly change and change back from a xenarthra-like state? When did it morph and morph back?


And the fact that Cretaceous mammals looked like Xenarthra is just the tip of the iceberg. I have more circumstantial evidence, none of which has to do with what mammals looked like after KPg or phylogenetic trees. Phylogenetic trees are ONE piece of evidence. So please forgive if the phylogenetic evidence alone from just one angle (after KPg) with no citations doesn't completely convince me of "dunno what it was but it wasn't Xenarthra-like."


I mean no disrespect to anyone but I have never encountered such opposition to legitimate questions before. I don't understand why legitimate questions should be returned with anger or insults.

I am not speaking of you, Ernest. I am speaking to you in regards to John. You have been polite and helpful and I thank you. But John doesn't want me to ask Christine questions, even when Christine speaks to me first. Christine addressed one piece of evidence, and John is trying to keep her from answering the rest of the evidence I can present. I guess I have to go elsewhere to get the info I need.


Now I will reread John's paper and see just how different the proposed LCA is from Xenarthrans, and I bet the difference won't be near as great as what was implied above. The major difference is likely that it's smaller and missing its shell. If cheek flanges are not on the list because of lack of them AFTER the KPG, the lineage before KPg is not being considered and I guess "cheek flanges" are yet another case of unexplained convergence. And I HATE cases of unexplained convergence. To me, they signify a need for more study and nothing else. Not looking for an environmental or genetic explanation for them is lazy, in my view.


Is there a backwards phylogenetic tree, leading from the ancestors to the LCA of placentals instead of using post KPg material? Shouldn't an ancestral model be tested against a descendent model? Shouldn't both yield the same result?

[J.LyonLayden]

If you don't like me making theories governed by natural laws to explain currently unexplained convergences, just remember I could invoke "morphic resonance" and send my ms to Rupert Sheldrake. It would get more press, make more money, and the unexplained convergences would still be better known to the public. I don't know why you dislike my attempts at explanations using only natural laws.

[J.LyonLayden]

And by the way you just gavce me the title. It's going to be called "unexplained Convergences" and I hope you don't continue to hinder me from finding scientific explanations for them, because I could care less who calls me a fringe scientist or a quack.

[John Harshman]

First, your theories are governed only by your ability to make spurious
connections and wave your arms; all this appeal to "natural laws" is in
your imagination only. Feel free to go for morphic resonance; it would
be just as plausible as what you're doing now.

[John Harshman]

The title of what? I've never called you a fringe scientist or a quack.
A fringe scientist is still a scientist, and you aren't. A quack is
specifically a medical crank. I've called you a crank and a crackpot.
Again, one thing that would help you is to follow Mark Twain's advice in
Fenimore Cooper's Literary Offenses: The author shall: Say what he is
proposing to say, not merely come near it. Use the right word, not its
second cousin. Good advice for any writer, especially one who wants to
be understood.

[J.LyonLayden]

From what I have seen in our debates, the above statements are built upon opinion and not science. They are also based on insufficient data, since you've never allowed me to present all of my evidence. I am simply asking you to let Christine answer questions and not butt in when the two of us have engaged in conversation. I have a right to ask questions. If you want to insult me for every question and statement I make, I'll have to learn to kill-file you. I'd rather not because I learn things from you. But Christine and I were talking, please stop butting in.

[J.LyonLayden]

On Thursday, December 14, 2017 at 2:25:03 PM UTC-5, John Harshman wrote:
> On 12/14/17 10:36 AM, J.LyonLayden wrote:
> > On Thursday, December 14, 2017 at 1:05:03 AM UTC-5, John Harshman wrote:
> >> On 12/13/17 9:22 PM, J.LyonLayden wrote:
> >>> On Thursday, December 14, 2017 at 12:15:03 AM UTC-5, erik simpson wrote:
> >>>> On Wednesday, December 13, 2017 at 8:55:02 PM UTC-8, J.LyonLayden wrote:
> >>>>> On Wednesday, December 13, 2017 at 10:50:02 PM UTC-5, John Harshman wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>> May I allow it an osteoderm for my hypothesis and check my results if I stop calling it Xenarthra?
> >>>>
> >>>> Of course not. The character matrix you use to evaluate tree hypotheses has to be
> >>>> honest. Fossils show what they show (not enough, usually), but you can't add
> >>>> anything to them.
> >>>
> >>> Good grief. Ok. How do you make any kind of hypothesis that might
> >>> explain a culmination of problems? Like Darwin was allowed to do?
> >>
> >>> How can I be allowed to make a hypothesis which might fill the "god
> >>> of the gaps?"
> >>
> >> It's hard to tell what you're even trying to say above. Once again I ask
> >> you to pay more attention when typing and reread for clarity before posting.
> >
> > And by the way you just gavce me the title. It's going to be called
> > "unexplained Convergences" and I hope you don't continue to hinder me
> > from finding scientific explanations for them, because I could care
> > less who calls me a fringe scientist or a quack.
>
> The title of what? I've never called you a fringe scientist or a quack.

My Time-Life style book that will explore various scientific and fringe explanations for convergences in the evolutionary tree.

I just thought of it thanks to you.

> A fringe scientist is still a scientist, and you aren't. A quack is
> specifically a medical crank. I've called you a crank and a crackpot.
> Again, one thing that would help you is to follow Mark Twain's advice in
> Fenimore Cooper's Literary Offenses: The author shall: Say what he is
> proposing to say, not merely come near it. Use the right word, not its
> second cousin. Good advice for any writer, especially one who wants to
> be understood.

Fine. Whether or not you think I'm a crank will have no bearing on book sales, neither for my fiction nor for "Unexplained Convergences" nor for "The Evolution of B-B-Q," the two latter of which will be in the non-fiction section.

Is that better?

[John Harshman]

Let me suggest that you are not qualified (meaning not degrees but
knowledge) to decide what my statements are built on. You also appear
not to know how usenet works. There are no private conversations, and in
fact Christine seldom replies. My "butting in" has nothing to do with that.

And your questions aren't precisely questions. They're of the "given
that the moon is made of cheese" variety, entailing false assumptions
almost every time. Nor am I insulting you; I'm just telling you what
your statements are like.

[John Harshman]

It sounds like a very unfortunate book, and I sincerely hope it doesn't
find a publisher.

>> A fringe scientist is still a scientist, and you aren't. A quack is
>> specifically a medical crank. I've called you a crank and a crackpot.
>> Again, one thing that would help you is to follow Mark Twain's advice in
>> Fenimore Cooper's Literary Offenses: The author shall: Say what he is
>> proposing to say, not merely come near it. Use the right word, not its
>> second cousin. Good advice for any writer, especially one who wants to
>> be understood.
>
> Fine. Whether or not you think I'm a crank will have no bearing on
> book sales, neither for my fiction nor for "Unexplained Convergences"
> nor for "The Evolution of B-B-Q," the two latter of which will be in
> the non-fiction section.
> Is that better?

So it's just money you're after here? Still, even for a silly crank
book, Twain's advice should be valuable.

[J.LyonLayden]

Yeah I know.
Fact: The cretaceous sister species of placentals had Xenarthran features
Fact: The first placental to diverge was Xenarthra
Therefore, the first placental may have had some things in common with Xenarthra.

Wow that's almost as ludicrous as Ancient Aliens.

[J.LyonLayden]

Nope. I'd like to have better explanations for the convergences I keep finding in the current evolutionary model. Google adwords says other people are wondering about these convergences too.

Scientists don't care about explaining them, so I will fulfill the need for possible answers. And hopefully make a little money for my service to society.

I will take Mark Twain's advice on my actual manuscript, but I don't think he expected his advice to be followed to the letter in every conversation between human beings.

[John Harshman]

Agreed. And neither of your facts are true. The Cretaceous sister
species of placentals was a non-placental eutherian, perhaps Maelestes,
Ukhaatherium, or Zalambdalestes, or some combination thereof, not what
you think. "The first placental to diverge" is a meaningless statement,
since it takes two to diverge, and they do it simultaneously. Now of
course the first placental had some things in common with Xenarthra,
just as it had some things in common with all its other descendants. It
may even have had a few features that are preserved only in Xenarthra,
but the way to find that out isn't to make vague pronouncements in
ignorance of the tree. It's to optimize characters on the tree, as
O'Leary et al. did. The simplest thing for you to do is look in the
supplementary information for the synapomorphies of Epitheria and then
suppose that a contrary state is likely to be shared by the ancestral
placental and Xenarthra. Here's what the supplement says:
"Synapomorphies include a deep premaxilla body (character 62), a
lacrimal excluded from the dorsal and ventral extremes of the orbital
rim (character 202), presence of a deciduous lower canine (character
1401), presence of a scapular notch (character 2974), absence of the
parafibula (character 3417), presence of a sylvian sulcus in the brain
(character 4465), and terrestrial, as opposed to scansorial, locomotion
(character 4538)."

[John Harshman]

You will note that if you deal with these convergences by changing the
tree, you will generate many more convergences than you explain. If you
deal with them by coming up with a meaningless ad hoc explanation you
will have just wasted everyone's time. The third course would be to come
up with a testable hypothesis and test it.

> Scientists don't care about explaining them, so I will fulfill the
> need for possible answers. And hopefully make a little money for my
> service to society.

Again with the conceit that scientists are idiots and only you know the
true way to do science. Scientists do explain many sorts of convergence,
mostly by comparison to extant species, comparative studies of
co-evolution on trees, and physical modeling. None of which you have
attempted.

> I will take Mark Twain's advice on my actual manuscript, but I don't
> think he expected his advice to be followed to the letter in every
> conversation between human beings.

He expected it to be followed by any competent person attempting to
communicate to readers, I would imagine. Which of these fails to
describe you?

[J.LyonLayden]

I'm not planning to change the tree. I might see what happens if I postulate an osteoderm, and then test it. I don't see why it would shake the very fabric of the unviverse though. The osteoderm convergence is already there, why would it create another convergence if I test the idea that it may have been present before 56 mya?

Only one taxa would have to lose the osteoderm before diverging into all other placental mammals.

But you know what? I might ditch the osteoderm idea. I'm only in the data gathering stage at present.

>
> > Scientists don't care about explaining them, so I will fulfill the
> > need for possible answers. And hopefully make a little money for my
> > service to society.
>
> Again with the conceit that scientists are idiots and only you know the
> true way to do science. Scientists do explain many sorts of convergence,
> mostly by comparison to extant species, comparative studies of
> co-evolution on trees, and physical modeling. None of which you have
> attempted.

They also claim superficial morphological resemblance when it's not actually superficial, and can be documented by multiple anatomical traits.

Example: aetosaurs and ankylosaurs.

It may not be common ancestry, but it's not just superficial at all.

In the case of multituberculates and Xenarthrans, the Cheek flanges could be a shared ancestor or a shared diet. I have more work to do.

I don't know why you keep insisting I'm dissing on all scientists. I've never heard of an aetosaur/ankylosaur specialist or a Triassic archosaur/Jurassic ornithischian specialist.

>
> > I will take Mark Twain's advice on my actual manuscript, but I don't
> > think he expected his advice to be followed to the letter in every
> > conversation between human beings.
>
> He expected it to be followed by any competent person attempting to
> communicate to readers, I would imagine. Which of these fails to
> describe you?

I don't think he would have chastised me so much for using "quack" instead of "crank" by accident. Maybe if I'd submitted it for publication he might have a problem.

[John Harshman]

Are you or are you not the person who is claiming that aetosaurs are
closely related to tritylodonts?

> I might see what happens if I
> postulate an osteoderm, and then test it. I don't see why it would
> shake the very fabric of the unviverse though. The osteoderm
> convergence is already there, why would it create another convergence
> if I test the idea that it may have been present before 56 mya?

What does "postulate an osteoderm" even mean, and how would you test it?

> Only one taxa would have to lose the osteoderm before diverging into
> all other placental mammals.

Yes, and that loss would have to be massively convergent. Or do you
think only gain of a feature could be convergent?

> But you know what? I might ditch the osteoderm idea. I'm only in the
> data gathering stage at present.

So every hypothesis you have advanced so far was just...what?

>>> Scientists don't care about explaining them, so I will fulfill the
>>> need for possible answers. And hopefully make a little money for my
>>> service to society.
>>
>> Again with the conceit that scientists are idiots and only you know the
>> true way to do science. Scientists do explain many sorts of convergence,
>> mostly by comparison to extant species, comparative studies of
>> co-evolution on trees, and physical modeling. None of which you have
>> attempted.
>
> They also claim superficial morphological resemblance when it's not
> actually superficial, and can be documented by multiple anatomical
> traits.

> Example: aetosaurs and ankylosaurs.

So you are still claiming that scientists are idiots who can't notice
this deep resemblance.

> It may not be common ancestry, but it's not just superficial at all.

> In the case of multituberculates and Xenarthrans, the Cheek flanges
> could be a shared ancestor or a shared diet. I have more work to do.

What sort of work were you planning?

> I don't know why you keep insisting I'm dissing on all scientists.
> I've never heard of an aetosaur/ankylosaur specialist or a Triassic
> archosaur/Jurassic ornithischian specialist.

Nobody is such an extreme specialist. And nobody is so stupid as to
ignore relevant fossils. You understand that vertebrate paleontologists
begin with a broad education in the characters of all sorts of animals,
right? Nobody who works on ankylosaurs is unaware of aetosaurs, or vice
versa.

>>> I will take Mark Twain's advice on my actual manuscript, but I don't
>>> think he expected his advice to be followed to the letter in every
>>> conversation between human beings.
>>
>> He expected it to be followed by any competent person attempting to
>> communicate to readers, I would imagine. Which of these fails to
>> describe you?
>
> I don't think he would have chastised me so much for using "quack"
> instead of "crank" by accident. Maybe if I'd submitted it for
> publication he might have a problem.

Yeah, Fennimore Cooper probably thought the same thing. At the very
least, shouldn't you have some consideration for your audience? Me, for
example.

[J.LyonLayden]

What is it convergent with? Only one ancestor has to lose the osteoderm before diversifying into the ancestor of all non-Xenarthran placentals.

I guess it's convergent with extant sloths of Xenarthra?

>
> > But you know what? I might ditch the osteoderm idea. I'm only in the
> > data gathering stage at present.
>
> So every hypothesis you have advanced so far was just...what?

A hypothesis. What's it supposed to be, a religion?

>
> >>> Scientists don't care about explaining them, so I will fulfill the
> >>> need for possible answers. And hopefully make a little money for my
> >>> service to society.
> >>
> >> Again with the conceit that scientists are idiots and only you know the
> >> true way to do science. Scientists do explain many sorts of convergence,
> >> mostly by comparison to extant species, comparative studies of
> >> co-evolution on trees, and physical modeling. None of which you have
> >> attempted.
> >
> > They also claim superficial morphological resemblance when it's not
> > actually superficial, and can be documented by multiple anatomical
> > traits.
>
> > Example: aetosaurs and ankylosaurs.
>
> So you are still claiming that scientists are idiots who can't notice
> this deep resemblance.
>
> > It may not be common ancestry, but it's not just superficial at all.
>
> > In the case of multituberculates and Xenarthrans, the Cheek flanges
> > could be a shared ancestor or a shared diet. I have more work to do.
>
> What sort of work were you planning?

It was just going to be a fiction story. That's still on, but now you've given me an idea for an "Ancient Mysteries" type book.

For each particular convergence, I'll summarize a fringe theory I find, such as Eugene McCarthy or I.D. or Ancient Aliens. Alien genetic manipulation or some shit. Then I'll summarize the scientific explanations.Then I'll summarize my alternatives to both. At the end of each chapter I'll let the reader choose between the three and suggest further reading.

I'll have it beta read by a crank and a scientist to make sure I'm not misrepresenting either. You'd be a great one.

The more I know the better my alternative will be.

>
> > I don't know why you keep insisting I'm dissing on all scientists.
> > I've never heard of an aetosaur/ankylosaur specialist or a Triassic
> > archosaur/Jurassic ornithischian specialist.
>
> Nobody is such an extreme specialist. And nobody is so stupid as to
> ignore relevant fossils. You understand that vertebrate paleontologists
> begin with a broad education in the characters of all sorts of animals,
> right? Nobody who works on ankylosaurs is unaware of aetosaurs, or vice
> versa.

I don't think they are infallible and I shouldn't by logical deduction. I didn't trust the ones who told me the Portuguese hominid was "convergent evolution" with Neanderthals. I could go on and on. This does not mean I think people are idiots.

[John Harshman]

No, it would have to be lost in every prior branch of the tree that
lacks osteoderms. That goes way, way back.

> I guess it's convergent with extant sloths of Xenarthra?

Not clear what you mean by that.

>>> But you know what? I might ditch the osteoderm idea. I'm only in the
>>> data gathering stage at present.
>>
>> So every hypothesis you have advanced so far was just...what?
>
> A hypothesis. What's it supposed to be, a religion?

But you've been defending a whole list of hypotheses. How can you do
that if you're still in the data-gathering stage?

I have a bad feeling about this.

> I'll have it beta read by a crank and a scientist to make sure I'm
> not misrepresenting either. You'd be a great one.

> The more I know the better my alternative will be.

The more you know the more your alternative will come to resemble the
standard theory, unless what you know ain't so.

>>> I don't know why you keep insisting I'm dissing on all scientists.
>>> I've never heard of an aetosaur/ankylosaur specialist or a Triassic
>>> archosaur/Jurassic ornithischian specialist.
>>
>> Nobody is such an extreme specialist. And nobody is so stupid as to
>> ignore relevant fossils. You understand that vertebrate paleontologists
>> begin with a broad education in the characters of all sorts of animals,
>> right? Nobody who works on ankylosaurs is unaware of aetosaurs, or vice
>> versa.
>
> I don't think they are infallible and I shouldn't by logical
> deduction. I didn't trust the ones who told me the Portuguese hominid
> was "convergent evolution" with Neanderthals. I could go on and on.
> This does not mean I think people are idiots.

Ah, but you have previously said that all your ideas were obvious.
Wouldn't it take an idiot to study a subject for years and miss the obvious?

[jillery]

On Thu, 14 Dec 2017 07:22:01 -0800, John Harshman

I didn't accuse you of anything. I'm just trying to reconcile your
statements above, where you first imply the fossil record can *not*
show order of appearance of characters, and then assert the fossil
record *can* show order of appearance by mapping said characters on a
phylogenetic tree, without explaining how doing so isn't using the
fossil record.

>The order of appearance in the fossil record can't show the order of
>appearance in time, but a phylogenetic tree using fossils, which doesn't
>incorporate any stratigraphic ordering, can show that order. The state
>on a particular branch is earlier in time than a state on any descendant
>branch.

It is possible for you to give a simplified, general explanation of
how to map characters on a phylogenetic tree? And how doing so shows
their order of appearance? Using examples of fossil whale characters
would be particularly relevant.

Poor proofreading on my part. My bad. I meant to ask: "Are there no
cases where fossils *are* distinguishable by character?"

>>> It may be impossible to
>>> distinguish the ancestral species from some fairly close relative.
>>
>> Same question as above. If there are cases where it's possible to
>> distinguish close relatives, what's wrong with recognizing them?
>
>We recognize them, but we can't say that either of them is ancestral to
>anything.

By "distinguishable" I mean to be able to identify their evolutionary
relationships, ie which is ancestral and which is descendant. IIUC
your statement immediately above, you know of *no* cases. Correct?

>>> Second, reversals do occur, so the real common ancestor may have what
>>> looks like an autapomorphy.
>>
>> I had to look up "autapomorphy", but I still don't understand your
>> point. Please clarify.
>
>What we expect of an ancestral species is that it will be exactly the
>same as a reconstructed ancestor, i.e. having 100% primitive character
>states. But if a character present in the ancestor is reversed (going
>from the derived back to the primitive state), it will look as if the
>ancestral fossil has an autapomorphy, removing it from the direct line
>of descent.

This is my working definition of autapomorphy:

"A derived trait that is unique to a particular taxon"

If you find that definition acceptable, please explain how that case
prevents the identification of ancestral species.

>>> And of course given the gappy nature of the record, and the ratio of
>>> known species to those that have existed, it's unlikely that we have
>>> found any particular ancestor.

[Ernest Major]

On 15/12/2017 08:07, jillery wrote:
> This is my working definition of autapomorphy:
>
> "A derived trait that is unique to a particular taxon"
>
> If you find that definition acceptable, please explain how that case
> prevents the identification of ancestral species.

Autapomorphy followed by reversal produces false negatives; it make a
species that is a true ancestor look as if it isn't, as it has a derived
character not shared with its descendants.

--
alias Ernest Major

[John Harshman]

Sorry if I was unclear. The order of appearance in the fossil record
does not show the order of appearance in time. The order of appearance
in a lineage on a phylogenetic tree, whether from fossils or not, does
show the order of appearance in time. Is that clear enough?

>> The order of appearance in the fossil record can't show the order of
>> appearance in time, but a phylogenetic tree using fossils, which doesn't
>> incorporate any stratigraphic ordering, can show that order. The state
>> on a particular branch is earlier in time than a state on any descendant
>> branch.
>
> It is possible for you to give a simplified, general explanation of
> how to map characters on a phylogenetic tree? And how doing so shows
> their order of appearance? Using examples of fossil whale characters
> would be particularly relevant.

It's hard to do this without graphics, and I don't have a tree of whale
phylogeny handy at the moment. But once you have a tree, you put
character changes on the branches that require the fewest total changes
over the entire tree. If change x happens on a branch that's ancestral
to a branch where change y happens, then change x happens before change y.

Lots of fossils are distinguishable by character. Of course when they
aren't we can't tell. There are however a great many modern species that
would not be distinguishable from fossils.

>>>> It may be impossible to
>>>> distinguish the ancestral species from some fairly close relative.
>>>
>>> Same question as above. If there are cases where it's possible to
>>> distinguish close relatives, what's wrong with recognizing them?
>>
>> We recognize them, but we can't say that either of them is ancestral to
>> anything.
>
> By "distinguishable" I mean to be able to identify their evolutionary
> relationships, ie which is ancestral and which is descendant. IIUC
> your statement immediately above, you know of *no* cases. Correct?

Ah, that's not what I would mean by "distinguishable". But yes, I know
of no cases in which we can say that any fossil species is ancestral to
any other. In order to do so you would have to know that the relevant
fossil record was complete, i.e. that you had in fact sampled the actual
ancestor, and you would have to be able to reliably sort fossils into
species. Neither of these is likely, and if it had happened in some
particular case there would be no way to be sure it had.

Now, we can in principle do one thing: if we can know that some group
actually is a species, and we know that it's paraphyletic to some other
species, then the first species is ancestral to the second. The most
common alleged case is brown bear vs. polar bear, but there are problems
with that, and it's certainly not due to fossil data anyway. It's not a
real solution.

>>>> Second, reversals do occur, so the real common ancestor may have what
>>>> looks like an autapomorphy.
>>>
>>> I had to look up "autapomorphy", but I still don't understand your
>>> point. Please clarify.
>>
>> What we expect of an ancestral species is that it will be exactly the
>> same as a reconstructed ancestor, i.e. having 100% primitive character
>> states. But if a character present in the ancestor is reversed (going
>>from the derived back to the primitive state), it will look as if the
>> ancestral fossil has an autapomorphy, removing it from the direct line
>> of descent.
>
> This is my working definition of autapomorphy:
>
> "A derived trait that is unique to a particular taxon"
>
> If you find that definition acceptable, please explain how that case
> prevents the identification of ancestral species.

Any species with an autapomorphy would not be considered an ancestor,
because it differs from the projected ancestor by that autapomorphy. In
the hypothetical case I'm talking about, that would be wrong because the
descendant had reversed the autapomorphy back tot he primitive state.
And revrsals do happen.

[J.LyonLayden]

On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
> On 12/13/17 5:40 AM, jillery wrote:

>Ah, but you have previously said that all your ideas were obvious.
>Wouldn't it take an idiot to study a subject for years and miss the obvious?

Not all. Few people outside of paleontological circles know about the cheek flanges, for instance. As for other examples that do seem obvious, have you stepped back and looked at your reaction to my ideas and questions over the last few weeks? I suspect it would be much the same in a classroom, and that you would have more power over your classroom than you have over what I say in this forum.


All that is required is that most professors have the same initial attitude as you do, which is evident in my experiences with them. A professor at GSU couldn't tell me how we know a particular species was a reptile, for instance....and became very nervous and judgemental just because I asked. Then she referred me to someone who knows more about Cretaceous reptiles, and the specialist wouldn't talk to me about it.
Just for that one question, this professor avoids me like the plague and looks at me funny every time I visit.

Because of one question.




Further, 20 somethings have not been watching science news as long as I have. They don't know as much about other disciplines as I do when they first enter their core classes. You did not seem up to date on the latest in continental drift understandings when our debates began, for instance.

I have watched science be found wrong over and over and over and over again for 40 years concerning similar assumptions to those I'm pointing out now.

[Mark Isaak]

On 12/15/17 8:04 AM, J.LyonLayden wrote:
> On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
>> On 12/13/17 5:40 AM, jillery wrote:
>> Ah, but you have previously said that all your ideas were obvious.
>> Wouldn't it take an idiot to study a subject for years and miss the obvious?
>
> Not all. Few people outside of paleontological circles know about the cheek flanges, for instance. As for other examples that do seem obvious, have you stepped back and looked at your reaction to my ideas and questions over the last few weeks? I suspect it would be much the same in a classroom, and that you would have more power over your classroom than you have over what I say in this forum.
>
>
> All that is required is that most professors have the same initial attitude as you do, which is evident in my experiences with them. A professor at GSU couldn't tell me how we know a particular species was a reptile, for instance....and became very nervous and judgemental just because I asked. Then she referred me to someone who knows more about Cretaceous reptiles, and the specialist wouldn't talk to me about it.
> Just for that one question, this professor avoids me like the plague and looks at me funny every time I visit.
>
> Because of one question.

I guarantee it was not just the question. It was how you responded to
the answer.

Very nearly all teachers love to teach students who want to learn. You
are not one of those students. Instead, you have an agenda you want to
push. Part of that agenda is the implicit assertion that essentially
all vertebrate paleontologists, at least relative to you, are idiots.
It is not surprising that professors react negatively to that.

--
Mark Isaak eciton (at) curioustaxonomy (dot) net
"Ignorance, allied with power, is the most ferocious enemy justice can
have." - James Baldwin

[J.LyonLayden]

No Mark. She answered the question with "It's a reptile, isn't it?" I replied "How do you tell it's a reptile?" She said "I don't know I'm not a marine paleontologist. Excuse me I have to go. Dr. Blahblahs hall is that way."

You know where she had to go? To talk to my friend for some made up reason. When I later joined them, she looked at me and said incredulously "You're with them?"


Now she gets notably nervous whenever I'm around now.

Just from two questions. I have seen similar reactions elsewhere.


I asked her because I DID want to learn. i went home and learned about fenestrae and fourth trochanters, without her help.


I learn things every day, and my previously held beliefs get changed on a weekly basis. It should be the same with all non-omniscient people until they die. That's how you keep the brain from stagnating.

But I am not a student at Georgia Southern. I'm was just a good friend of the guy who donated most of their fossils, but he died recently.

[John Harshman]

On 12/15/17 8:04 AM, J.LyonLayden wrote:

> On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
>> On 12/13/17 5:40 AM, jillery wrote:
>> Ah, but you have previously said that all your ideas were obvious.
>> Wouldn't it take an idiot to study a subject for years and miss the obvious?
>
> Not all. Few people outside of paleontological circles know about the
> cheek flanges, for instance.

That's where "study a subject" comes in. Don't dodge.

> As for other examples that do seem
> obvious, have you stepped back and looked at your reaction to my
> ideas and questions over the last few weeks? I suspect it would be
> much the same in a classroom, and that you would have more power over
> your classroom than you have over what I say in this forum.

Whatever does this have to do with a classroom? My reaction to your
ideas (often expressed as loaded questions) is what any rational
person's would be. Don't dodge.

> All that is required is that most professors have the same initial
> attitude as you do, which is evident in my experiences with them. A
> professor at GSU couldn't tell me how we know a particular species
> was a reptile, for instance....and became very nervous and
> judgemental just because I asked. Then she referred me to someone who
> knows more about Cretaceous reptiles, and the specialist wouldn't
> talk to me about it.

> Just for that one question, this professor avoids me like the plague
> and looks at me funny every time I visit.
> Because of one question.

You don't actually know why he avoids you. I suspect it's because he
doesn't want to deal with cranks. I can certainly see why a scientist
wouldn't want to talk to you.

What species are we talking about here? And what do you mean by
"reptile", exactly?

> Further, 20 somethings have not been watching science news as long as
> I have. They don't know as much about other disciplines as I do when
> they first enter their core classes. You did not seem up to date on
> the latest in continental drift understandings when our debates
> began, for instance.

I don't think you know much about the subject, actually.

> I have watched science be found wrong over and over and over and over
> again for 40 years concerning similar assumptions to those I'm
> pointing out now.

I doubt it, since you have never managed so far to point out an
assumption anyone actually makes.

[J.LyonLayden]

On Friday, December 15, 2017 at 2:00:03 PM UTC-5, John Harshman wrote:
> On 12/15/17 8:04 AM, J.LyonLayden wrote:
> > On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
> >> On 12/13/17 5:40 AM, jillery wrote:
> >> Ah, but you have previously said that all your ideas were obvious.
> >> Wouldn't it take an idiot to study a subject for years and miss the obvious?
> >
> > Not all. Few people outside of paleontological circles know about the
> > cheek flanges, for instance.
>
> That's where "study a subject" comes in. Don't dodge.

I'm not getting this question as it pertains to your last question, but I'll take a stab.
The more obvious convergence examples, such as the late sauropods on Madagascar who were first mistaken for bipedal ornithischians, don't get questioned because no one really cares.

The better known convergences, such as ankylosaurs and post-KPg horned/spiked taxa tentatively placed into Pantestudine with a 90 mya ghost lineage, don't get questioned because the question runs the risk of ridicule.

I'm old enough now I don't care if I get ridiculed.

>
> > As for other examples that do seem
> > obvious, have you stepped back and looked at your reaction to my
> > ideas and questions over the last few weeks? I suspect it would be
> > much the same in a classroom, and that you would have more power over
> > your classroom than you have over what I say in this forum.
> Whatever does this have to do with a classroom? My reaction to your
> ideas (often expressed as loaded questions) is what any rational
> person's would be. Don't dodge.

In most of my college classes, it was not the professor who discouraged me from asking questions that might challenge consensus. It was the students. Especially the pretty girls would often refrain "This isn't going to be on the test."

>
> > All that is required is that most professors have the same initial
> > attitude as you do, which is evident in my experiences with them. A
> > professor at GSU couldn't tell me how we know a particular species
> > was a reptile, for instance....and became very nervous and
> > judgemental just because I asked. Then she referred me to someone who
> > knows more about Cretaceous reptiles, and the specialist wouldn't
> > talk to me about it.
>
> > Just for that one question, this professor avoids me like the plague
> > and looks at me funny every time I visit.
> > Because of one question.
>
> You don't actually know why he avoids you. I suspect it's because he
> doesn't want to deal with cranks. I can certainly see why a scientist
> wouldn't want to talk to you.

then you have your answer. Why would you think it would be different in the classrom?

>
> What species are we talking about here? And what do you mean by
> "reptile", exactly?
>
> > Further, 20 somethings have not been watching science news as long as
> > I have. They don't know as much about other disciplines as I do when
> > they first enter their core classes. You did not seem up to date on
> > the latest in continental drift understandings when our debates
> > began, for instance.
>
> I don't think you know much about the subject, actually.

Ok. Think what you would like.

>
> > I have watched science be found wrong over and over and over and over
> > again for 40 years concerning similar assumptions to those I'm
> > pointing out now.
>
> I doubt it, since you have never managed so far to point out an
> assumption anyone actually makes.

Your whole field assumes that no synapsid ever grew a bigger muscle attached to the supraorbital region and has not tested the alternative. Your whole field assumes that no therapsid has ever grown a tail as large and long as an archosaur's and has not tested the alternative.

[*Hemidactylus*]

J.LyonLayden <joseph...@gmail.com> wrote:
>
[snip]

>
> In most of my college classes, it was not the professor who discouraged
> me from asking questions that might challenge consensus. It was the
> students. Especially the pretty girls would often refrain "This isn't
> going to be on the test."
>

In my biology undergrad experience female classmates were very competitive.
And there were female teacher’s assistants. And I worked with female
graduate students assisting them with their research projects in biology.
None of them had the attitude you fake quote above.

[John Harshman]

On 12/15/17 11:18 AM, J.LyonLayden wrote:
> On Friday, December 15, 2017 at 2:00:03 PM UTC-5, John Harshman wrote:
>> On 12/15/17 8:04 AM, J.LyonLayden wrote:
>>> On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
>>>> On 12/13/17 5:40 AM, jillery wrote:
>>>> Ah, but you have previously said that all your ideas were obvious.
>>>> Wouldn't it take an idiot to study a subject for years and miss the obvious?
>>>
>>> Not all. Few people outside of paleontological circles know about the
>>> cheek flanges, for instance.
>>
>> That's where "study a subject" comes in. Don't dodge.
>
> I'm not getting this question as it pertains to your last question, but I'll take a stab.

> The more obvious convergence examples, such as the late sauropods on
> Madagascar who were first mistaken for bipedal ornithischians, don't
> get questioned because no one really cares.

> The better known convergences, such as ankylosaurs and post-KPg
> horned/spiked taxa tentatively placed into Pantestudine with a 90 mya
> ghost lineage, don't get questioned because the question runs the
> risk of ridicule.

It doesn't, really, as long as you're sincere in asking and the question
contains no false premises. There's your problem. Your questions always
come with the tacit message "I know more than you do, and scientists are
idiots". That last is what we're talking about, and you haven't
addressed it.

> I'm old enough now I don't care if I get ridiculed.

You should care, however, if you are ridiculed for good reasons.

>>> As for other examples that do seem
>>> obvious, have you stepped back and looked at your reaction to my
>>> ideas and questions over the last few weeks? I suspect it would be
>>> much the same in a classroom, and that you would have more power over
>>> your classroom than you have over what I say in this forum.
>> Whatever does this have to do with a classroom? My reaction to your
>> ideas (often expressed as loaded questions) is what any rational
>> person's would be. Don't dodge.
>
> In most of my college classes, it was not the professor who
> discouraged me from asking questions that might challenge consensus.
> It was the students. Especially the pretty girls would often refrain
> "This isn't going to be on the test."

I'm not responsible for your college classes. Still dodging.

>>> All that is required is that most professors have the same initial
>>> attitude as you do, which is evident in my experiences with them. A
>>> professor at GSU couldn't tell me how we know a particular species
>>> was a reptile, for instance....and became very nervous and
>>> judgemental just because I asked. Then she referred me to someone who
>>> knows more about Cretaceous reptiles, and the specialist wouldn't
>>> talk to me about it.
>>
>>> Just for that one question, this professor avoids me like the plague
>>> and looks at me funny every time I visit.
>>> Because of one question.
>>
>> You don't actually know why he avoids you. I suspect it's because he
>> doesn't want to deal with cranks. I can certainly see why a scientist
>> wouldn't want to talk to you.
>
> then you have your answer. Why would you think it would be different in the classrom?

What question do I have my answer for? The only question I've asked you
here is "Wouldn't it take an idiot to study a subject for years and miss
the obvious?"

It's completely rational not to want to deal with cranks, one on one and
most especially in the classroom, where a persistent crank can be
disruptive to learning. But that seems to have nothing to do with the
question I asked.

>> What species are we talking about here? And what do you mean by
>> "reptile", exactly?
>>
>>> Further, 20 somethings have not been watching science news as long as
>>> I have. They don't know as much about other disciplines as I do when
>>> they first enter their core classes. You did not seem up to date on
>>> the latest in continental drift understandings when our debates
>>> began, for instance.
>>
>> I don't think you know much about the subject, actually.
>
> Ok. Think what you would like.
>
>
>>
>>> I have watched science be found wrong over and over and over and over
>>> again for 40 years concerning similar assumptions to those I'm
>>> pointing out now.
>>
>> I doubt it, since you have never managed so far to point out an
>> assumption anyone actually makes.
>
> Your whole field assumes that no synapsid ever grew a bigger muscle
> attached to the supraorbital region and has not tested the
> alternative.

That's just incorrect. Every phylogenetic analysis tests every
alternative. What you call an assumption is a conclusion from the data.
In order to fit anything with an upper temporal fenestra into Synapsida,
you would have to invoke a great many convergences.

> Your whole field assumes that no therapsid has ever
> grown a tail as large and long as an archosaur's and has not tested
> the alternative.

Same answer, but with the addition that "a big tail" is not the reason
for a fourth trochanter. The caudofemoralis is only slightly about
moving the tail (which it does, a bit, in some species, because tail and
hind limb are in many species cordinated). It's mostly about retracting
the femur. Note that the muscle originates only from the proximal-most
caudal vertebrae, which are present even in species with the shortest
tails; you, for example.

Here's your main problem: you spin a fantasy out of the first thing you
read, and then you interpret all subsequent information so as to conform
to your fantasy. Try for a little less a priori bias.

[J.LyonLayden]

I wasn't saying that only women did it. I should have been more clear. I was saying that I only cared when pretty girls did it, and maybe pretty girls did it a little more. I have observed that attractive people are often not so much into science, but I would not call that observation a fact. it's just a general suspicion.

[erik simpson]

You must be a real hunk.

[J.LyonLayden]

On Friday, December 15, 2017 at 2:55:03 PM UTC-5, John Harshman wrote:
> On 12/15/17 11:18 AM, J.LyonLayden wrote:
> > On Friday, December 15, 2017 at 2:00:03 PM UTC-5, John Harshman wrote:
> >> On 12/15/17 8:04 AM, J.LyonLayden wrote:
> >>> On Wednesday, December 13, 2017 at 9:55:04 AM UTC-5, John Harshman wrote:
> >>>> On 12/13/17 5:40 AM, jillery wrote:
> >>>> Ah, but you have previously said that all your ideas were obvious.
> >>>> Wouldn't it take an idiot to study a subject for years and miss the obvious?
> >>>
> >>> Not all. Few people outside of paleontological circles know about the
> >>> cheek flanges, for instance.
> >>
> >> That's where "study a subject" comes in. Don't dodge.
> >
> > I'm not getting this question as it pertains to your last question, but I'll take a stab.
>
> > The more obvious convergence examples, such as the late sauropods on
> > Madagascar who were first mistaken for bipedal ornithischians, don't
> > get questioned because no one really cares.
>
> > The better known convergences, such as ankylosaurs and post-KPg
> > horned/spiked taxa tentatively placed into Pantestudine with a 90 mya
> > ghost lineage, don't get questioned because the question runs the
> > risk of ridicule.
>
> It doesn't, really, as long as you're sincere in asking and the question
> contains no false premises. There's your problem. Your questions always
> come with the tacit message "I know more than you do, and scientists are
> idiots". That last is what we're talking about, and you haven't
> addressed it.

I don't mean to convey that. I certainly don't think Darwin was an idiot because he didn't know about continental drift. It had been previously introduced, and he could have figured it out himself, but he didn't.

I don't think Neuton was an idiot just because he hadn't figured out Einstein's formula yet. I don't really know what you are getting at. new discoveries and understandings don't make anyone an idiot.

>
> > I'm old enough now I don't care if I get ridiculed.
> You should care, however, if you are ridiculed for good reasons.

That's why I am working out ideas here instead of jumping to press.

>
> >>> As for other examples that do seem
> >>> obvious, have you stepped back and looked at your reaction to my
> >>> ideas and questions over the last few weeks? I suspect it would be
> >>> much the same in a classroom, and that you would have more power over
> >>> your classroom than you have over what I say in this forum.
> >> Whatever does this have to do with a classroom? My reaction to your
> >> ideas (often expressed as loaded questions) is what any rational
> >> person's would be. Don't dodge.

How would you expect the things I've proposed to you to come up in a classroom and be given their due? Of course your answer will be "they don't deserve any due" and there you have your answer.

Whether my questions have been legitimate is up to the reader to decide.

> >
> > In most of my college classes, it was not the professor who
> > discouraged me from asking questions that might challenge consensus.
> > It was the students. Especially the pretty girls would often refrain
> > "This isn't going to be on the test."
> I'm not responsible for your college classes. Still dodging.

What kind of answer would you like? I don't think there is a world-wide conspiracy, if that's what you are asking. I think the ignoring of my questions about fenestrae and fourth trochanters is "all in a days work" and has nothing to do with conspiracy.

>
> >>> All that is required is that most professors have the same initial
> >>> attitude as you do, which is evident in my experiences with them. A
> >>> professor at GSU couldn't tell me how we know a particular species
> >>> was a reptile, for instance....and became very nervous and
> >>> judgemental just because I asked. Then she referred me to someone who
> >>> knows more about Cretaceous reptiles, and the specialist wouldn't
> >>> talk to me about it.
> >>
> >>> Just for that one question, this professor avoids me like the plague
> >>> and looks at me funny every time I visit.
> >>> Because of one question.
> >>
> >> You don't actually know why he avoids you. I suspect it's because he
> >> doesn't want to deal with cranks. I can certainly see why a scientist
> >> wouldn't want to talk to you.
> >
> > then you have your answer. Why would you think it would be different in the classrom?
>
> What question do I have my answer for? The only question I've asked you
> here is "Wouldn't it take an idiot to study a subject for years and miss
> the obvious?"

No it wouldn't. It wouldn't require an idiot at all. I don't see how I can be clearer without giving examples, as I have above.

>
> It's completely rational not to want to deal with cranks, one on one and
> most especially in the classroom, where a persistent crank can be
> disruptive to learning. But that seems to have nothing to do with the
> question I asked.
>
> >> What species are we talking about here? And what do you mean by
> >> "reptile", exactly?
> >>
> >>> Further, 20 somethings have not been watching science news as long as
> >>> I have. They don't know as much about other disciplines as I do when
> >>> they first enter their core classes. You did not seem up to date on
> >>> the latest in continental drift understandings when our debates
> >>> began, for instance.
> >>
> >> I don't think you know much about the subject, actually.
> >
> > Ok. Think what you would like.
> >
> >
> >>
> >>> I have watched science be found wrong over and over and over and over
> >>> again for 40 years concerning similar assumptions to those I'm
> >>> pointing out now.
> >>
> >> I doubt it, since you have never managed so far to point out an
> >> assumption anyone actually makes.

Neanderthals never ever no never contributed to our gene pool, and you're a crank if you think they did . the late portuguese cro-magnon was an example of convergence, and does not say otherwise.(19870s through early 90s)

> >
> > Your whole field assumes that no synapsid ever grew a bigger muscle
> > attached to the supraorbital region and has not tested the
> > alternative.
>
> That's just incorrect. Every phylogenetic analysis tests every
> alternative.

Including the chance that supraorbital fenestrae and fourth trochanters have arisen in the lineage?

What you call an assumption is a conclusion from the data.
> In order to fit anything with an upper temporal fenestra into Synapsida,
> you would have to invoke a great many convergences.

I think there would be no more than already exist and would like to see it tested.

>
> > Your whole field assumes that no therapsid has ever
> > grown a tail as large and long as an archosaur's and has not tested
> > the alternative.
>
> Same answer, but with the addition that "a big tail" is not the reason
> for a fourth trochanter. The caudofemoralis is only slightly about
> moving the tail (which it does, a bit, in some species, because tail and
> hind limb are in many species cordinated). It's mostly about retracting
> the femur. Note that the muscle originates only from the proximal-most
> caudal vertebrae, which are present even in species with the shortest
> tails; you, for example.

Right. And if mine grew as long as an archosaurs in some descendent, I would need a fourth trochanter in order to control it.

>
> Here's your main problem: you spin a fantasy out of the first thing you
> read, and then you interpret all subsequent information so as to conform
> to your fantasy. Try for a little less a priori bias.

That's not how I work at all.

[J.LyonLayden]

I'm a hunk who's into science, and that seems kinda rare.

[J.LyonLayden]

Haha, I meant Newton up there. I think I'm going to name a character Ike Neutron now

[John Harshman]

Yeah, what you don't mean to convey isn't really relevant. Your
"questions" reek of condescension. And we're not talking about "new
discoveries and understandings" we're talking about what is "obvious",
remember?

>>> I'm old enough now I don't care if I get ridiculed.

>> You should care, however, if you are ridiculed for good reasons.

> That's why I am working out ideas here instead of jumping to press.

If that's what you're really here for, you should be less condescending,
less willing to assume that scientists are blind idiots, and more
willing to take corrections.

>>>>> As for other examples that do seem
>>>>> obvious, have you stepped back and looked at your reaction to my
>>>>> ideas and questions over the last few weeks? I suspect it would be
>>>>> much the same in a classroom, and that you would have more power over
>>>>> your classroom than you have over what I say in this forum.
>>>> Whatever does this have to do with a classroom? My reaction to your
>>>> ideas (often expressed as loaded questions) is what any rational
>>>> person's would be. Don't dodge.
>
> How would you expect the things I've proposed to you to come up in a
> classroom and be given their due? Of course your answer will be "they
> don't deserve any due" and there you have your answer.

My answer to what? I would not expect the things you have proposed to
come up in a classroom. But if they did, I would expect some discussion
along the lines of what we've had here, though the first response should
be adequate for anyone who isn't firmly attached to their speculations.
Persistence in the face of that response would disrupt the class, and I
would expect the instructor to suggest a discussion outside of class.
Persist enough and you would be recognized as a crank, and perhaps avoided.

> Whether my questions have been legitimate is up to the reader to decide.

I'm the reader. I've decided.

>>> In most of my college classes, it was not the professor who
>>> discouraged me from asking questions that might challenge consensus.
>>> It was the students. Especially the pretty girls would often refrain
>>> "This isn't going to be on the test."
>> I'm not responsible for your college classes. Still dodging.

> What kind of answer would you like? I don't think there is a
> world-wide conspiracy, if that's what you are asking. I think the
> ignoring of my questions about fenestrae and fourth trochanters is
> "all in a days work" and has nothing to do with conspiracy.

A none-dodge answer would be good. Nobody mentioned a conspiracy. If you
remember, the question was about you thinking that scientists are
idiots. You're the one who brought classrooms into it, for no apparent
reason.

>>>>> All that is required is that most professors have the same initial
>>>>> attitude as you do, which is evident in my experiences with them. A
>>>>> professor at GSU couldn't tell me how we know a particular species
>>>>> was a reptile, for instance....and became very nervous and
>>>>> judgemental just because I asked. Then she referred me to someone who
>>>>> knows more about Cretaceous reptiles, and the specialist wouldn't
>>>>> talk to me about it.
>>>>
>>>>> Just for that one question, this professor avoids me like the plague
>>>>> and looks at me funny every time I visit.
>>>>> Because of one question.
>>>>
>>>> You don't actually know why he avoids you. I suspect it's because he
>>>> doesn't want to deal with cranks. I can certainly see why a scientist
>>>> wouldn't want to talk to you.
>>>
>>> then you have your answer. Why would you think it would be different in the classrom?
>>
>> What question do I have my answer for? The only question I've asked you
>> here is "Wouldn't it take an idiot to study a subject for years and miss
>> the obvious?"
>
> No it wouldn't. It wouldn't require an idiot at all. I don't see how
> I can be clearer without giving examples, as I have above.

You have given no examples. You could be clearer by explaining what you
mean.

>> It's completely rational not to want to deal with cranks, one on one and
>> most especially in the classroom, where a persistent crank can be
>> disruptive to learning. But that seems to have nothing to do with the
>> question I asked.
>>
>>>> What species are we talking about here? And what do you mean by
>>>> "reptile", exactly?
>>>>
>>>>> Further, 20 somethings have not been watching science news as long as
>>>>> I have. They don't know as much about other disciplines as I do when
>>>>> they first enter their core classes. You did not seem up to date on
>>>>> the latest in continental drift understandings when our debates
>>>>> began, for instance.
>>>>
>>>> I don't think you know much about the subject, actually.
>>>
>>> Ok. Think what you would like.
>>>
>>>
>>>>
>>>>> I have watched science be found wrong over and over and over and over
>>>>> again for 40 years concerning similar assumptions to those I'm
>>>>> pointing out now.
>>>>
>>>> I doubt it, since you have never managed so far to point out an
>>>> assumption anyone actually makes.
>
> Neanderthals never ever no never contributed to our gene pool, and
> you're a crank if you think they did . the late portuguese cro-magnon
> was an example of convergence, and does not say otherwise.(19870s
> through early 90s)

An assumption, or the best conclusion based on data available at the
time? At any rate, that assumption isn't anything we've been talking
about so far, and that's what I was asking about.

>>> Your whole field assumes that no synapsid ever grew a bigger muscle
>>> attached to the supraorbital region and has not tested the
>>> alternative.
>>
>> That's just incorrect. Every phylogenetic analysis tests every
>> alternative.
>
> Including the chance that supraorbital fenestrae and fourth trochanters have arisen in the lineage?

Yes.

>> What you call an assumption is a conclusion from the data.
>> In order to fit anything with an upper temporal fenestra into Synapsida,
>> you would have to invoke a great many convergences.
>
> I think there would be no more than already exist and would like to see it tested.

What is your basis for thinking that? As for tests, you have been given
quite a few references. Have you looked at any of them?

>>> Your whole field assumes that no therapsid has ever
>>> grown a tail as large and long as an archosaur's and has not tested
>>> the alternative.
>>
>> Same answer, but with the addition that "a big tail" is not the reason
>> for a fourth trochanter. The caudofemoralis is only slightly about
>> moving the tail (which it does, a bit, in some species, because tail and
>> hind limb are in many species cordinated). It's mostly about retracting
>> the femur. Note that the muscle originates only from the proximal-most
>> caudal vertebrae, which are present even in species with the shortest
>> tails; you, for example.
>
> Right. And if mine grew as long as an archosaurs in some descendent,
> I would need a fourth trochanter in order to control it.

Whoosh.

>> Here's your main problem: you spin a fantasy out of the first thing you
>> read, and then you interpret all subsequent information so as to conform
>> to your fantasy. Try for a little less a priori bias.
>
> That's not how I work at all.

Based on observation, you are incorrect in this belief.

[J.LyonLayden]

Is this so? Then you should have no problem with me copying and pasting your objections to each point we've discussed and my responses to them on my blog. They should be enough to quell the idea from the minds of all readers, no?

>
> > Whether my questions have been legitimate is up to the reader to decide.
>
> I'm the reader. I've decided.

You won't be the only reader, and after I've done my phylogenetic and parsimony work I will include all objections I have encountered here with utmost duty. I will also include my responses to such objections. Whether the objections are paraphrased depends upon your consent and blessing.

>
> >>> In most of my college classes, it was not the professor who
> >>> discouraged me from asking questions that might challenge consensus.
> >>> It was the students. Especially the pretty girls would often refrain
> >>> "This isn't going to be on the test."
> >> I'm not responsible for your college classes. Still dodging.
>
> > What kind of answer would you like? I don't think there is a
> > world-wide conspiracy, if that's what you are asking. I think the
> > ignoring of my questions about fenestrae and fourth trochanters is
> > "all in a days work" and has nothing to do with conspiracy.
> A none-dodge answer would be good. Nobody mentioned a conspiracy. If you
> remember, the question was about you thinking that scientists are
> idiots. You're the one who brought classrooms into it, for no apparent
> reason.

Well I don't think scientists are idiots. I think that previous assumptions get overturned at a regular frequency.

BIG assumptions.

>
> >>>>> All that is required is that most professors have the same initial
> >>>>> attitude as you do, which is evident in my experiences with them. A
> >>>>> professor at GSU couldn't tell me how we know a particular species
> >>>>> was a reptile, for instance....and became very nervous and
> >>>>> judgemental just because I asked. Then she referred me to someone who
> >>>>> knows more about Cretaceous reptiles, and the specialist wouldn't
> >>>>> talk to me about it.
> >>>>
> >>>>> Just for that one question, this professor avoids me like the plague
> >>>>> and looks at me funny every time I visit.
> >>>>> Because of one question.
> >>>>
> >>>> You don't actually know why he avoids you. I suspect it's because he
> >>>> doesn't want to deal with cranks. I can certainly see why a scientist
> >>>> wouldn't want to talk to you.
> >>>
> >>> then you have your answer. Why would you think it would be different in the classrom?
> >>
> >> What question do I have my answer for? The only question I've asked you
> >> here is "Wouldn't it take an idiot to study a subject for years and miss
> >> the obvious?"
> >
> > No it wouldn't. It wouldn't require an idiot at all. I don't see how
> > I can be clearer without giving examples, as I have above.
> You have given no examples. You could be clearer by explaining what you
> mean.

I think that if anyone has ever questioned the importance of the traits I've mentioned, or suggested any of the things I've suggested, they didn't get very far because they were dissuaded from their inquiries. Just like people were once dissuaded from theorizing that the Earth revolved around the sun.

>
> >> It's completely rational not to want to deal with cranks, one on one and
> >> most especially in the classroom, where a persistent crank can be
> >> disruptive to learning. But that seems to have nothing to do with the
> >> question I asked.
> >>
> >>>> What species are we talking about here? And what do you mean by
> >>>> "reptile", exactly?

What does this question refer to?

> >>>>
> >>>>> Further, 20 somethings have not been watching science news as long as
> >>>>> I have. They don't know as much about other disciplines as I do when
> >>>>> they first enter their core classes. You did not seem up to date on
> >>>>> the latest in continental drift understandings when our debates
> >>>>> began, for instance.
> >>>>
> >>>> I don't think you know much about the subject, actually.
> >>>
> >>> Ok. Think what you would like.
> >>>
> >>>
> >>>>
> >>>>> I have watched science be found wrong over and over and over and over
> >>>>> again for 40 years concerning similar assumptions to those I'm
> >>>>> pointing out now.
> >>>>
> >>>> I doubt it, since you have never managed so far to point out an
> >>>> assumption anyone actually makes.
> >
> > Neanderthals never ever no never contributed to our gene pool, and
> > you're a crank if you think they did . the late portuguese cro-magnon
> > was an example of convergence, and does not say otherwise.(19870s
> > through early 90s)
> An assumption, or the best conclusion based on data available at the
> time? At any rate, that assumption isn't anything we've been talking
> about so far, and that's what I was asking about.

When I was a kid, there was controversy over what killed the dinosaurs. Now there is virtually none.

It was tentative whether birds had evolved from dinosaurs, and some scientists vehemently opposed the idea and were given press time like the others.

There was more oxygen in the Cretaceous, not less.

Believing in Holocene archaics was as nutty as believing in Bigfoot 20 years ago.

We had disproven Lemuria as an explanation for lemur distribution via continental drift, but no one explained the distribution of lemurs adequately. Now we find that Mauritia could have provided the same landbridge as the proposed Lemuria. We may have named it Mauritia instead of Lemuria to kind of cover up the mistake.

That's kind of what they're doing right now with the Out of Africa vs. Multiregionalist debate of the 20th century. Both have been proven correct, but OoA received all of the credit.

>
> >>> Your whole field assumes that no synapsid ever grew a bigger muscle
> >>> attached to the supraorbital region and has not tested the
> >>> alternative.
> >>
> >> That's just incorrect. Every phylogenetic analysis tests every
> >> alternative.
> >
> > Including the chance that supraorbital fenestrae and fourth trochanters have arisen in the lineage?
>
> Yes.

Can you show me examples?

>
> >> What you call an assumption is a conclusion from the data.
> >> In order to fit anything with an upper temporal fenestra into Synapsida,
> >> you would have to invoke a great many convergences.
> >
> > I think there would be no more than already exist and would like to see it tested.
>
> What is your basis for thinking that? As for tests, you have been given
> quite a few references. Have you looked at any of them?

My basis is that I find it highly unlikely that supraorbital fenestrae only arose once over 300 million years ago and never arose again, while all other fenestra arose and disappeared multiple times. Same with fourth trochanters over 250 million years ago. Preliminary searches have lent some merit to my concerns.

[jillery]

Because of the incomplete and granular nature of the fossil record,
there are lots of reasons for false negatives, not just from what you
describe above. I'm just surprised there are no true positives,
autapomorphy notwithstanding.

[jillery]

On Fri, 15 Dec 2017 07:13:21 -0800, John Harshman

Your claim is clear. What remains unclear is how to apply character
data from the fossil record to a phylogenetic tree. I accept it might
be difficult to explain in a text froup. I shall look it up.

As I pointed out to Ernest Major, I understand there are lots of false
negatives. I'm not asking about them. I am asking if there are no
true positives.

I'm confused. The definition says a trait unique to a taxon. If a
species has that trait, how can it differ from the projected ancestor,
which by definition would also have that trait?

[Ernest Major]

On 16/12/2017 07:11, jillery wrote:
> On Fri, 15 Dec 2017 12:14:39 +0000, Ernest Major
> <{$to$}@meden.demon.co.uk> wrote:
>
>> On 15/12/2017 08:07, jillery wrote:
>>> This is my working definition of autapomorphy:
>>>
>>> "A derived trait that is unique to a particular taxon"
>>>
>>> If you find that definition acceptable, please explain how that case
>>> prevents the identification of ancestral species.
>>
>> Autapomorphy followed by reversal produces false negatives; it make a
>> species that is a true ancestor look as if it isn't, as it has a derived
>> character not shared with its descendants.
>
>
> Because of the incomplete and granular nature of the fossil record,
> there are lots of reasons for false negatives, not just from what you
> describe above. I'm just surprised there are no true positives,
> autapomorphy notwithstanding.

There might be true positives (real ancestors): but how do you tell
whether you have the ancestor, or a sibling species?

>
> --
> I disapprove of what you say, but I will defend to the death your right to say it.
>
> Evelyn Beatrice Hall
> Attributed to Voltaire
>

--
alias Ernest Major

[J.LyonLayden]

On Saturday, December 16, 2017 at 8:35:03 AM UTC-5, Ernest Major wrote:
> On 16/12/2017 07:11, jillery wrote:
> > On Fri, 15 Dec 2017 12:14:39 +0000, Ernest Major
> > <{$to$}@meden.demon.co.uk> wrote:
> >
> >> On 15/12/2017 08:07, jillery wrote:
> >>> This is my working definition of autapomorphy:
> >>>
> >>> "A derived trait that is unique to a particular taxon"
> >>>
> >>> If you find that definition acceptable, please explain how that case
> >>> prevents the identification of ancestral species.
> >>
> >> Autapomorphy followed by reversal produces false negatives; it make a
> >> species that is a true ancestor look as if it isn't, as it has a derived
> >> character not shared with its descendants.
> >
> >
> > Because of the incomplete and granular nature of the fossil record,
> > there are lots of reasons for false negatives, not just from what you
> > describe above. I'm just surprised there are no true positives,
> > autapomorphy notwithstanding.
>
> There might be true positives (real ancestors): but how do you tell
> whether you have the ancestor, or a sibling species?

Couldn't we call it an "ancestor candidate?"
Here's the problem I see. It is accepted that a stem archosaur developed mandibular and occipital fenestrae as well as a fourth trochanter.

But inside archosaur, many species don't have one or more of those things.
So we assume they lost them. But there are crocodylians of the Triassic with no antorbital fenestrae, and crocodylians in their direct lineage of the Cretaceous who HAD antorbital fenestrae, and modern crocs don't have them again.

So why is it ok to attribute evolutionary processes to a stem-archosaur, but not ok to attribute traits to various crocodylian groups?

We are allowed to say fenestrae opened in stem-archosaurs, but we are not allowed to say they opened and closed and opened again in the crocodylians. But in reality, we don't have any more proof of one process than the other.

[erik simpson]

Please don't bring up the ancestor-candidate nonsense. If you just slow down
for a minute and think: fossil record is very incomplete, many diagnostic
characters don't fossilize readily anyway. How can you possibly make any
positive statement about ancestry? this isn't a new outcome of "cladophilia",
this has been known to paleontologists for a long time. "There's no reason
it couldn't have been an ancestor" is such a weak statement that it's useless.

[J.LyonLayden]

I just think it's pretty obvious we evolved from an australopithecine and not some other ghost lineage descended from Ardipithecus.

[J.LyonLayden]

When I put forth a statement on archosaurs, must I say "Fenestrae MAY have opened and closed multiple times in archosaurs?"

Then why don't I have to say "fenestrae MAY have opened in a stem-archosaur and MAY have closed in extant crocodylians?"

[John Harshman]

It's pretty simple, really. The common method is parsimony: assuming you
have settled on a tree, each character is mapped so as to have the
smallest possible number of changes.

There might be, but the point is that we have no way to distinguish them
from false positives.

This is about mapping characters on a tree. If a trait is gained and
then lost in the immediate descendant, the most parsimonious mapping is
to assume that it was gained and not lost, and that the species having
that trait is off on a little branch all its own, distinct from the
ancestral node, which would be reconstructed as not having that trait.

The projected ancestor, in other words, would not have that trait by
definition.

[christi...@brown.edu]

"Multituberculates are the closest things we have to placentals in the Late Cretaceous"

If you mean "closer than monotremes", perhaps. Otherwise, no. They are quite unlike therians in many respects, dentally, cranially, and postcranially.

"When did the sister taxa of Multituberculates that led to placentals have time to rapidly change and change back from a xenarthra-like state? "

It didn't. All we know about gondwanatheres is that they had hypselodont molars, something that has evolved repeatedly amongst mammals. They were also tiny.

"If almost everything in the Cretaceous closely related to placentals is Xenarthran-like,"

Nothing in the Cretaceous is xenarthran-like, whether closely related to placentals or not.

Your obsession with xenarthrans has nothing to do with the actual facts of mammalian evolution. Xenarthrans are a derived clade of mammals, whether phylogentically basal or not. No Cretaceous mammal looked specifically like a Xenarthran, not even Vintana (that jugal flange is seen in macropodids as well as in a very few xenarthrans).

The example I gave previously about ratites being phylogentically basal birds, but early birds not being large flightless terrestrial herbivores, still stands.

[J.LyonLayden]

On Saturday, December 16, 2017 at 2:45:03 PM UTC-5, christi...@brown.edu wrote:
> "Multituberculates are the closest things we have to placentals in the Late Cretaceous"
>
> If you mean "closer than monotremes", perhaps. Otherwise, no. They are quite unlike therians in many respects, dentally, cranially, and postcranially.

There are so few therians. They are so small and specialized. They scream "diverged from something more generalized and probably bigger" to me.

But I have only just begun to learn phylogenetics.

>
> "When did the sister taxa of Multituberculates that led to placentals have time to rapidly change and change back from a xenarthra-like state? "
>
> It didn't. All we know about gondwanatheres is that they had hypselodont molars, something that has evolved repeatedly amongst mammals. They were also tiny.
>
> "If almost everything in the Cretaceous closely related to placentals is Xenarthran-like,"
>
> Nothing in the Cretaceous is xenarthran-like, whether closely related to placentals or not.
>
> Your obsession with xenarthrans has nothing to do with the actual facts of mammalian evolution. Xenarthrans are a derived clade of mammals, whether phylogentically basal or not. No Cretaceous mammal looked specifically like a Xenarthran, not even Vintana (that jugal flange is seen in macropodids as well as in a very few xenarthrans).

Thank you I will take a look at them.

>
> The example I gave previously about ratites being phylogentically basal birds, but early birds not being large flightless terrestrial herbivores, still stands.

Didn't birds evolve from maniraptorans, which were larger and flightless? I didn't pinpoint a time between 160 mya and 66 mya for divergence from Xenarthra-like.

[jillery]

Are you saying that in principle there can be no cases where it can be
stated with reasonable certainty specific fossil species share an
ancestral/descendant relationship? Or are you going to continue to
argue that a majority of cases allows you to ignore any exceptions?

[jillery]

On Sat, 16 Dec 2017 13:34:48 +0000, Ernest Major

<{$to$}@meden.demon.co.uk> wrote:

>On 16/12/2017 07:11, jillery wrote:
>> On Fri, 15 Dec 2017 12:14:39 +0000, Ernest Major
>> <{$to$}@meden.demon.co.uk> wrote:
>>
>>> On 15/12/2017 08:07, jillery wrote:
>>>> This is my working definition of autapomorphy:
>>>>
>>>> "A derived trait that is unique to a particular taxon"
>>>>
>>>> If you find that definition acceptable, please explain how that case
>>>> prevents the identification of ancestral species.
>>>
>>> Autapomorphy followed by reversal produces false negatives; it make a
>>> species that is a true ancestor look as if it isn't, as it has a derived
>>> character not shared with its descendants.
>>
>>
>> Because of the incomplete and granular nature of the fossil record,
>> there are lots of reasons for false negatives, not just from what you
>> describe above. I'm just surprised there are no true positives,
>> autapomorphy notwithstanding.
>
>There might be true positives (real ancestors): but how do you tell
>whether you have the ancestor, or a sibling species?

If you truly can't tell the difference, then why does it matter?

[erik simpson]

Never say never, and I'm hardly an authority, but I would be amazed if any
ancestor-descendant example could be unambiguously determined pre-Pleistocene.
The closer you get to the present, the easier it should be, but without DNA
data I'd bet it still isn't certain.

[jillery]

On Sat, 16 Dec 2017 15:04:18 -0800 (PST), erik simpson

>> >Please don't bring up the ancestor-candidate nonsense. If you just slow down
>> >for a minute and think: fossil record is very incomplete, many diagnostic
>> >characters don't fossilize readily anyway. How can you possibly make any
>> >positive statement about ancestry? this isn't a new outcome of "cladophilia",
>> >this has been known to paleontologists for a long time. "There's no reason
>> >it couldn't have been an ancestor" is such a weak statement that it's useless.
>>
>>
>> Are you saying that in principle there can be no cases where it can be
>> stated with reasonable certainty specific fossil species share an
>> ancestral/descendant relationship? Or are you going to continue to
>> argue that a majority of cases allows you to ignore any exceptions?
>>
>

>Never say never, and I'm hardly an authority, but I would be amazed if any
>ancestor-descendant example could be unambiguously determined pre-Pleistocene.
>The closer you get to the present, the easier it should be, but without DNA
>data I'd bet it still isn't certain.

No one mentioned certainty. Do you no longer accept inferences to the
best explanation?

[erik simpson]

Accept inferences to what? Best explanation to what? I don't see what you're
getting at. I was talking about the problem of determining ancestry of
fossil species, which by general agreement among paleontologists can't be
established. You can certainly talk about relatedness, but you can't take the
last step.

[Mark Isaak]

On 12/15/17 11:18 AM, J.LyonLayden wrote:

Here's an article I think you would be interested in, about a major
revision to dinosaur phylogeny:

Stephanie Keep, "Wouldn’t It Be Interesting To Test That?",
NCSE Blog, 4/20/2017,
https://ncse.com/blog/2017/04/wouldn-t-it-be-interesting-to-test-that-0018516

--
Mark Isaak eciton (at) curioustaxonomy (dot) net
"Ignorance, allied with power, is the most ferocious enemy justice can
have." - James Baldwin

[jillery]

On Sun, 17 Dec 2017 08:24:26 -0800 (PST), erik simpson

>Accept inferences to what? Best explanation to what?

Since you asked, the point you challenged, still preserved in the
quoted text above, is the utility of the phrase "ancestor-candidate".
You admitted, also still preserved in the quoted text above, that one
can't exclude the possibility of identifying fossil species which are
identifiable as ancestor candidates by their characters. So, even as
I agree that one can never be certain about which fossil species are
ancestral/descendant, ISTM perverse to say that you wouldn't accept
that as a reasonable inference in some specific cases.

>I don't see what you're
>getting at. I was talking about the problem of determining ancestry of
>fossil species, which by general agreement among paleontologists can't be
>established. You can certainly talk about relatedness, but you can't take the
>last step.

[erik simpson]

Have it your way (you usually do). Present your reasonable inference and we'll
see. What would you expect to be able to conclude from such an instance?
Speaking of perversity, Peter is very strong on this point, but I can't see the
point. We agree (apparently) that we can't be certain; I have no objections to
you or anyone else inferring whatever they like. If you want a fight, look
elsewhere.

[jillery]

On Sun, 17 Dec 2017 14:14:54 -0800 (PST), erik simpson
<eastsi...@gmail.com> wrote:

>Have it your way (you usually do).

Aren't you the testy one.