[_ Old Earth _] Article of Whale and Dolphin Evolution

[Barbarian]

(Crying rock asserts large fossil gaps)

Barbarian asks for some substantiation:
..Sounds like a testable assertion. What stage in the evolution of modern whales do you think is missing from the fossil record?.."

You're begging the question.

You're dodging the question. You asserted gaps, and now you apparently can't show us any.

Barbarian observes:
"...BTW, genetic analysis shows whales are related to ungulates..."

Sure, they're all mammals.

"Ungulate" doesn't mean "mammal." I thought you knew.

What's your point?

You made an assertion you can't substantiate.

Barbarian observes:
"...just as the fossil evidence shows..."

Again, begging the question.

I gave you a chance to show us, but you dodged it. If you ever do find one of those mythical gaps, be sure to tell us about it.

 

[Crying Rock]

(Crying rock asserts large fossil gaps)

Barbarian asks for some substantiation:
..Sounds like a testable assertion. What stage in the evolution of modern whales do you think is missing from the fossil record?.."

You're begging the question.

You're dodging the question. You asserted gaps, and now you apparently can't show us any.

Barbarian observes:
"...BTW, genetic analysis shows whales are related to ungulates..."

[quote:3vectjsr]Sure, they're all mammals.

"Ungulate" doesn't mean "mammal." I thought you knew.

What's your point?

You made an assertion you can't substantiate.

Barbarian observes:
"...just as the fossil evidence shows..."

Again, begging the question.

I gave you a chance to show us, but you dodged it. If you ever do find one of those mythical gaps, be sure to tell us about it.[/quote:3vectjsr]

Barb:

...Sounds like a testable assertion. What stage in the evolution of modern whales do you think is missing from the fossil record?.."

CR:

You're begging the question.

Barb:

You're dodging the question. You asserted gaps, and now you apparently can't show us any.

Barb:

...If you ever do find one of those mythical gaps, be sure to tell us about it...

CR:

There's a huge gap: That between land mammals and sea mammals.

Show me, step by step, a seamless fossil record demonstrating evolution from Pakicetus:

http://farm1.static.flickr.com/113/3024 ... 2748_o.jpg

to Mysticetes and Odontocetes:

http://fascinatingly.com/wp-content/upl ... _whale.jpg

http://api.ning.com/files/BWjRgBHaS*Cx3 ... lphins.jpg

Barb:

"...BTW, genetic analysis shows whales are related to ungulates..."

CR:

Sure, they're all mammals.

Barb:

"Ungulate" doesn't mean "mammal." I thought you knew.

Barb:

"...BTW, genetic analysis shows whales are "related" to ungulates..."

CR:

Ungulate- "...One traditional grouping of mammals..."

http://www.ucmp.berkeley.edu/mammal/eut ... ulate.html

Show me a step by step, seamless genetic evolution from Pakicetus:

http://farm1.static.flickr.com/113/3024 ... 2748_o.jpg

to Mysticetes and Odontocetes:

http://fascinatingly.com/wp-content/upl ... _whale.jpg

http://api.ning.com/files/BWjRgBHaS*Cx3 ... lphins.jpg

 

[Barbarian]

There's a huge gap: That between land mammals and sea mammals.

That's a testable assertion, too. Tell me what you think a transitional between land mammals and sea mammals would look like.

Show me, step by step, a seamless fossil record demonstrating evolution from Pakicetus:

"Seamless" would mean no steps at all, but one organism smoothly changing over time. That's not how evolution works. But as you admitted by declining to mention one, there are no "large gaps" now. From Pakicetus, first there's this:

Indohyus. Skull structure and general skeleton quite like Pakicetus, but heavier bones and oxygen isotope ratios that indicate it spent a lot of time in water. Probably a lot like some small Asian deer that are dense enough to walk along the bottom of steams.

BTW, it's extremely unlikely that either of these species were in the direct line to modern whales; it would be extremely lucky to get the very organism that gave rise to the next step. These are just very close to the lines that gave rise to modern whales.

Before we go on, you should either admit that there are no large gaps, or show one to us.

(Barbarian notes that genetic analysis confirms the relationship of whales to hoofed mammals)

Sure, they're all mammals.

Barbarian observes:
"Ungulate" doesn't mean "mammal." I thought you knew.

Ungulate- "...One traditional grouping of mammals..."

Yep. But genetic analysis shows whales related to ungulates, not just mammals in general. Another, entirely different line of evidence confirms the ungulate origin of whales.

 

[lordkalvan]

"Lord":

Are you quite incapable of explaining why the evidence I have presented fails to persuade you of either the likelihood of evolution or the probability that whales evolved from land-dwelling mammals?

Sorry to irritate you so much by, you know, actually asking you to present your case and define your terms more precisely rather than just accepting Nuh-huh, 'taint so! as a reasoned rebuttal of arguments and evidence supporting the evolutionary history of whales.

Because the fossil gaps are too large.

Well, it's a start. Which fossil gaps are 'too large'? All of them? What do you mean by 'too large'? Are there any fossil gaps that you regard as 'just right'? At what point do they become 'small enough'?

The genetic evidence is unavailable.

No, it isn't. You have been directed towards it. You may disagree with it, but you should at least say why rather than simply denying that it doesn't exist at all.

Your argument is quite unconvincing.

It may well be, but yours is non-existent.

If you don't understand my objections then I'm sorry.

I understand Nuh-huh, 'taint so!, but it scarcely constitutes a reasoned objection, nor does it provide us with an explanation of your understanding of the origin of whales and what evidence supports it.

You are passionate but not persuasive.

What would be 'persuasive', then? Something you think you know you can't be given?

 

[Crying Rock]

LK and Barb,

You guys still don't seem to get it. You are the ones making the claim that whales evolved from land dwelling mammals. The onus is not on me to disprove your case. The onus is upon you to prove your case. So far neither of you have attempted to make a decent case that whales evolved from land dwelling mammals.

One more time: please demonstrate a seamless genetic and fossil record that such evolution ever occurred. If you can't do that then your case is mere conjecture.

 

[Barbarian]

You guys still don't seem to get it.

We get it. You made a claim of a huge gap between land mammals and whales. When asked to support that claim, you ran. Nothing new there. You always run when you're asked to support such claims.

You are the ones making the claim that whales evolved from land dwelling mammals.

I just showed you that you were wrong about no transitional between Pakicetus and more aquatic whales. Would you like to see the next step? I'm assuming, since you ran when I asked you to show me a large gap, that you're not going to support your claim. It would be a pleasant surprise if you'd at least try, though.

 

[Crying Rock]

Barb:

“…I just showed you that you were wrong about no transitional between Pakicetus and more aquatic whales. Would you like to see the next step?..â€

Please. That’s what I’ve been asking you and LK all along. So far you have shown two land dwelling mammals, their spurious “evolutionary relation†, and neither are whales:

Pakicetus:

http://en.wikipedia.org/wiki/Fileakicetus_BW.jpg

Indohyus:

http://en.wikipedia.org/wiki/File:Indohyus_BW.jpg

These are whales:

http://www.kspc.org/blog/pix/2009/whales.jpg

http://matmantra.files.wordpress.com/20 ... whale1.jpg

 

[lordkalvan]

Barb:

“…I just showed you that you were wrong about no transitional between Pakicetus and more aquatic whales. Would you like to see the next step?..â€

Please. That’s what I’ve been asking you and LK all along. So far you have shown two land dwelling mammals, their spurious “evolutionary relation†, and neither are whales...

From the import of this post you do not seem to understand the difference between the statement that these animals are whales and the statement these animals are likely ancestral to whales. If you believe the evolutionary relationship is 'spurious', you need to explain why it is 'spurious' (in which case, 'the fossil gaps are too large' is not really explanatory, especially if you decline to share with us at what point the 'fossil gaps' become small enough to satisfy your demands. Seamlessness, given the fragmentary nature of the fossil record, is, of course, an impossible demand if you mean by the word what I suppose you to mean - but then I guess that is why you have phrased it in such a way.

 

[lordkalvan]

....There's a huge gap: That between land mammals and sea mammals....

Given that biologists and comparative anatomists see the vestigial and atavistic features of whales such as ear-twitching muscles, pelvic girdles and hind-limbs as indicative of descent from land-dwelling ancestral animals, a view supported by developmental embryology and molecular genetics, why do you suppose the gap is as huge as you grandly proclaim?

 

[lordkalvan]

You guys still don't seem to get it.

We get it. What you don't get is that this is supposed to be a discussion, not simply a one-way street where every time we present an argument or evidence, Nuh-huh! 'Taint so! does not constitute a reasoned rebuttal.

You are the ones making the claim that whales evolved from land dwelling mammals. The onus is not on me to disprove your case. The onus is upon you to prove your case.

We have presented several pieces of evidence that support this argument. If you think they are incorrect, you need to critique them and present a better explanation for the origin of whales. You do have one, I presume?

So far neither of you have attempted to make a decent case that whales evolved from land dwelling mammals.

Not so. We have more than attempted this, we have cited a number of examples and references that support the argument.

One more time: please demonstrate a seamless genetic and fossil record that such evolution ever occurred. If you can't do that then your case is mere conjecture.

The evolutionary record is fragmentary and incomplete. You need to consider the preponderance of evidence and explain why that preponderance is better explained by a different interpretation.

 

[Barbarian]

The classic Gish dodge; "I'll become an evolutionist when I see a whale with legs."

(Ambulocetus is discovered)

"It isn't a whale; whales don't have legs."

;)

 

[Crying Rock]

Barb:

“…I just showed you that you were wrong about no transitional between Pakicetus and more aquatic whales. Would you like to see the next step?..â€

Please. That’s what I’ve been asking you and LK all along. So far you have shown two land dwelling mammals, their spurious “evolutionary relation†, and neither are whales:

Pakicetus:

http://en.wikipedia.org/wiki/Fileakicetus_BW.jpg

Indohyus:

http://en.wikipedia.org/wiki/File:Indohyus_BW.jpg

These are whales:

http://www.kspc.org/blog/pix/2009/whales.jpg

http://matmantra.files.wordpress.com/20 ... whale1.jpg

Barb:

“…I just showed you that you were wrong about no transitional between Pakicetus and more aquatic whales. Would you like to see the next step?..â€

Please.

And while your at it, lets deal with some unfinished business: what are the differences between Pakicetus and Indohyus' feet?

Barb:

If you ever do find one of those mythical gaps, be sure to tell us about it.

CR:

There's a huge gap: That between land mammals and sea mammals.

Show me, step by step, a seamless fossil record demonstrating evolution from Pakicetus:

http://farm1.static.flickr.com/113/3024 ... 2748_o.jpg

to Mysticetes and Odontocetes:

http://www.baleines.ca/v2/images/mysticete.gif

http://naturescrusaders.files.wordpress ... -whale.jpg

 

[Barbarian]

Ambulocetus.

Unlike Indohyus, which spent a lot of time in water, but was primarily adapted to land, Ambulocetus spent a lot of time on land, but was primarily adapted to water. Oxygen isotopes still indicate a fresh water existence, but this one is larger, more seal-like with legs adapted to swimming, instead of walking. (But it could still walk)

Want to see the next step?

 

[Crying Rock]

Ambulocetus.

Unlike Indohyus, which spent a lot of time in water, but was primarily adapted to land, Ambulocetus spent a lot of time on land, but was primarily adapted to water. Oxygen isotopes still indicate a fresh water existence, but this one is larger, more seal-like with legs adapted to swimming, instead of walking. (But it could still walk)

Want to see the next step?

Before we move on to Ambulocetus, will you please answer the question I asked in my last post:

CR:

...lets deal with some unfinished business: what are the differences between Pakicetus and Indohyus' feet?

And legs, tails, ribs, back, etc...?

We have to at least demonstrate a firm evolutionary relationship between the first two "transitional fossils" before we can move on to their supposed evolutionary relationship with Ambulocetus and those further up the supposed tree.

I don't think 56-40ma, supposedly unique fossilized ear bones of land-dwelling organisms, clinches your case.

“…Other experts, however, caution that although the scenario is possible, the ancestry analysis is based on incomplete data. Researchers "really thought the book was closed on this," says Annalisa Berta, an evolutionary biologist at San Diego State University. "To suggest that this fossil somehow is closer than hippos, that's a big deal—I'm just not convinced…"

“…Whatever its relationship with whales, Indohyus was probably not a direct predecessor of them, Thewissen says, because the specimen, unearthed 30 years ago in Kashmir, dates to roughly two million years after the earliest known cetacean fossils…â€

“…The new analysis does not yet unseat the hippo as cetaceans' kissing cousin, because it only takes into account anatomical features, not molecular ones, says Maureen O'Leary, a professor in the department of anatomical sciences at Stony Brook University…â€

http://www.scientificamerican.com/artic ... ale-cousin

Barb:

If you ever do find one of those mythical gaps, be sure to tell us about it.

Barb:

"Seamless" would mean no steps at all, but one organism smoothly changing over time. That's not how evolution works. But as you admitted by declining to mention one, there are no "large gaps" now. From Pakicetus, first there's this:

Indohyus. Skull structure and general skeleton quite like Pakicetus, but heavier bones and oxygen isotope ratios that indicate it spent a lot of time in water. Probably a lot like some small Asian deer that are dense enough to walk along the bottom of steams.

BTW, it's extremely unlikely that either of these species were in the direct line to modern whales...

So, by your own reasoning, these two specimens shouldn't even be used as examples of whale evolution. They didn't even evolve into whales. Correct? And if they didn't even evolve into whales, what do "unique" ear bones have to do with evidence except to say that other species besides those "leading up" to whales had them? I'd say this is a huge gap.
No evidence of an evolutionary relationship at all: feet, limbs, ribs, back, ears, etc...

After we address the above issues we can move onto Ambulocetus.

Ambulocetus.

Unlike Indohyus, which spent a lot of time in water, but was primarily adapted to land, Ambulocetus spent a lot of time on land, but was primarily adapted to water. Oxygen isotopes still indicate a fresh water existence, but this one is larger, more seal-like with legs adapted to swimming, instead of walking. (But it could still walk)

"...Ambulocetus (or the "'walking whale'") was an early cetacean that could walk as well as swim. It lived during early Eocene some 50-49 million years ago..."

http://en.wikipedia.org/wiki/Ambulocetus


"...Indohyus ("India's pig") is a genus of extinct artiodactyl known from Eocene fossils in Asia, purported to be approximately 48 million years old..."

http://en.wikipedia.org/wiki/Indohyus

 

[Barbarian]

Barbarian, regarding the supposed absence of an intermediate between Indohyus and whales with non-functional legs:

Unlike Indohyus, which spent a lot of time in water, but was primarily adapted to land, Ambulocetus spent a lot of time on land, but was primarily adapted to water. Oxygen isotopes still indicate a fresh water existence, but this one is larger, more seal-like with legs adapted to swimming, instead of walking. (But it could still walk)

Want to see the next step?

...lets deal with some unfinished business: what are the differences between Pakicetus and Indohyus' feet?

Well, let's see... both have hooves. But Ambulocetus is somewhat more evolved for swimming. Unlike Indohus, which seems to have mostly walked along the bottom, and swam secondarily, Ambulocetus has large, webbed feet (but still with hooves) that allow it to swim more efficiently.

And legs,

Same bones and musculature, but the legs are relatively smaller, and shorter. Ambulocetus could still walk about on land, but less capably than Indohyus.

tails,

Indohyus and Ambulocetus both have rather robust tails, but the tail of Ambulocetus is relatively shorter.

ribs,

What ribs we have of Indohyus, show that they were more robust than those of most ungulates of that size. Like Ambulocetus.

back

Like most small ungulates, Indohyus has a relatively flexible, doglike spine, that allows for a good amount of flexion. This allows for quick darting movements. Ambulocetus has a similar spine, well-adapted to dorsoventral flexion. It swam with the same movement that small ungulates gallop. This is why whales have horizontal flukes instead of vertical fins, as fish do.

etc....?

The skull of both are whale-like.

The Telltale Involucrum
Indohyus shares several dental features with early whales, including a front-to-back arrangement of the incisors, high crowns on its back molars, and similar wear facets. But the clincher is a little thickened lip of bone on the inside of the middle ear cavity, known as the involucrum, which likely assists in hearing underwater. Until this week, only whales were known to possess this feature. But one of the new Indohyus skulls shows that this little raoellid had a lovely little involucrum as well (see it here, and be amazed).
http://vladimirkorsakov.blogspot.com/20 ... tions.html

Precisely what we'd expect to see for an intermediate between Pakicetus and Ambulocetus.

“…Whatever its relationship with whales, Indohyus was probably not a direct predecessor of them, Thewissen says, because the specimen, unearthed 30 years ago in Kashmir, dates to roughly two million years after the earliest known cetacean fossils…â€

Ah, we're back to the "if you're alive, your uncle has to be dead" argument. Sorry, not convincing. No one says that the specimens includes the one that gave rise to present whales. They are just very close to the line that did. It would be remarkable if we happened to find the precise one. And a group does not have to go extinct, just because one population evolved into something else.

Barbarian suggests:
If you ever do find one of those mythical gaps, be sure to tell us about it.

So, by your own reasoning, these two specimens shouldn't even be used as examples of whale evolution. They didn't even evolve into whales. Correct?

See above. Even honest creationists realize that transitionals are almost never the precise animal that gave rise to the next species.

And if they didn't even evolve into whales, what do "unique" ear bones have to do with evidence except to say that other species besides those "leading up" to whales had them?

It just shows that the "gap" you claimed to have, doesn't exist. There was indeed a closely-related population that was precisely intermediate between Pakicetus and Ambulocetus.

I'd say this is a huge gap.

Of course you would. But your denials are not a substitute for evidence.

No evidence of an evolutionary relationship at all: feet, limbs, ribs, back, ears, etc...

Surprise.

Now that you see the many transitional characteristics between the two, are you ready to move on to the next step?

Or will we see some more dithering?

 

[jasoncran]

what if they aint transitioning at all. just similarities,

since we can only observe the small changes. could it be that we are speculating that they transition when its just normal fluctuations in the allele frequencies.
how long have we been looking at those freqs.
less than 100 yrs maybe. a little more.

 

[Barbarian]

what if they aint transitioning at all. just similarities,

We can test that with living creatures. Turns out, we never see homologous organs outside of common descent. DNA analyses confirms this, and we know that works, because we can trace the descent of organisms known by other means.

since we can only observe the small changes. could it be that we are speculating that they transition when its just normal fluctuations in the allele frequencies.

That's how evolution works. For example, there are a number of species of most fossil organisms, but the differences are quite small. When they accumulate enough changes, we give them a new genus. Hence, there must be some significant differences between any two genera in the sequence. The point is, as I just explained to CR, that the similarities are too numerous and too detailed to deny what they are. Only whales and their ancestors have bulla and ear structure like that.

 

[jasoncran]

but we havent been able to see each and every single change, holes buddy!
never will by your admission!

so...

what if we have creatures that are soo similiar in nature that we assume that they must have a common descendant and ancestor because of the so called million micro changes..
but dont have any transition at all.

since we cant directly observe we automatically presume that the change must be happening

the horsehoe crab hasnt changed nor has the nautilus did that beneficial mutations stop for some reason

odd i dont recall that mutations were so selective.

 

[lordkalvan]

...the horsehoe crab hasnt changed....

Eh, yes it has: there are obvious significant morphological differences amongst fossil and living species that even a layman can notice and comment on: modern Xiphosura is quite distinct from extinct Palaeolimulus, for example.

...nor has the nautilus...

Again, not correct:

Two genera of nautilus survive to the present day, Nautilus and Allonautilus, but it isn't at all obvious whether these living nautiluses are representative of their extinct kin as well. For a start the living species belong to a single family, the Nautilidae, that doesn't go back any further than the Late Triassic (about 215 million years ago); the greatest variety of nautiluses had already lived and died long before then. Ecologically the living species seem to be quite specialised too... On the other hand, the living species of nautilus do have some features typical of the primitive molluscs from which the cephalopods evolved, such as a robust shell and multiple pairs of gills. The coiled shell divided into gas-filled chambers and providing both buoyancy and protection is at least superficially similar to those possessed by another cephalopod group, the Ammonoidea, which will be discussed later on. But it is important to note that coiling evolved independently in the two groups. The first ammonites, like the early nautiluses, had straight shells and in fact it seems most probable that both ammonites and coleoids evolved from the straight-shelled nautiluses.

Source: http://www.thecephalopodpage.org/evolution.php

...beneficial mutations stop for some reason

odd i dont recall that mutations were so selective.

There is no evidence that mutations ever stop occurring, but most mutations are neutral and positive ones are not always necessarily selected for. Amongst the complicating factors that have to be taken into account are, for example, the extent of genetic fixing of existing traits that may be subject to mutation. There are also multiple types of mutations, each of which has a different effect and consequence for the impacted trait.

 

[Barbarian]

but we havent been able to see each and every single change, holes buddy!
never will by your admission!

so...

We don't know every ancestor of yours since Adam, so we can safely reject Adam as the first human, by your reasoning.

what if we have creatures that are soo similiar in nature that we assume that they must have a common descendant and ancestor because of the so called million micro changes..
but dont have any transition at all.

Name me two major groups, said to be evolutionarily connected, that lack a transitional.

since we cant directly observe we automatically presume that the change must be happening

We just go with the evidence. As you see in the case of whales, all of it points to evolution. None of it is contrary to evolution.

the horsehoe crab hasnt changed nor has the nautilus did that beneficial mutations stop for some reason

Lord Kalvan has pointed out that this is not true. Each of these now is a much smaller group of species than was once true. But they are not the same species that lived hundreds of millions of years ago. They too have evolved.

odd i dont recall that mutations were so selective.

They aren't. But natural selection is. It's called "stabilizing selection." When a well-adapted organism lives in an environment that is unchanging in selective pressures, natural selection will actually prevent much evolution. Darwin himself pointed this out.