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

[Crying Rock]

CR:

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

Barb:

...Well, let's see... both have hooves…

I guess I’m behind. I thought a Pakicetus skull is all we have. Are there some recent Pakicetus discoveries that have preserved legs, pelvises, tails, ribs, backs, etc...

CR:

...And legs…

Barb:

...Same bones and musculature, but the legs are relatively smaller, and shorter.…

I guess I’m behind. I thought a Pakicetusis skull is all we have.

CR:

…tails …

Barb:

…Indohyus…have rather robust tails…â€

And what kind of tails do Pakicetus have?

CR:

…ribs …

Barb:

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

And what kind of ribs do Pakicetus have?

CR:

…back …

Barb:

… 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…

And what kind of backs do Pakicetus have?

…Surprise.

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

You’re kidding, right?

Please, lets continue this discussion of the evolutionary relationship between Pakicetus, Indohyus and whales before we move onto Ambulocetus. If we can't straighten out the relationships of the basal land dwelling species then the whole hypothesis is groundless.

 

[jasoncran]

if evolution is so true then, and adamantly defending after all since its like the foreniscal evidence gathering, and a guilty verdict has been rendered and sentence mete out. Then why are you all still looking for evidence.

oh wait ...

this is science. not forensics.. my bad

 

[lordkalvan]

if evolution is so true then, and adamantly defending after all since its like the foreniscal evidence gathering, and a guilty verdict has been rendered and sentence mete out. Then why are you all still looking for evidence.

oh wait ...

this is science. not forensics.. my bad

I think the argument is that the theory of evolution has been largely vindicated by multiple strands of independent, consilient evidence, but that the evolutionary history of individual species and genuses - as in the case of the discussion around whales - is obscured by the fragmentary nature of the fossil record and the difficulties inherent in acquiring a precise understanding of the relationships revealed by molecular genetics. That creationists seize so quickly on areas of apparent uncertainty - such as the absence of a 'seamless' transition from a land-dwelling ancestor to the whales we see today - is more reflective of their hopes of invalidating the whole theory by finding 'flaws' in specific instances.

 

[lordkalvan]

....I guess I’m behind. I thought a Pakicetus skull is all we have. Are there some recent Pakicetus discoveries that have preserved legs, pelvises, tails, ribs, backs, etc...

Yes, you're behind:

Complete skeletons were discovered in 2001, revealing that Pakicetus was primarily a land animal, about the size of a wolf, and very similar in form to the related mesonychids.

Source: http://en.wikipedia.org/wiki/Pakicetus

I guess I’m behind. I thought a Pakicetusis skull is all we have.

See above.

And what kind of tails do Pakicetus have?

....And what kind of ribs do Pakicetus have?

...And what kind of backs do Pakicetus have?

Happy to oblige:

Source: http://www.edwardtbabinski.us/whales/ev ... fossil.gif

 

[Barbarian]

Note the robust tail, flexible spine, and yes, hooves.

Early on, it was assumed that Pakicetus was just a primitive whale, based on the whale-like skull. Later, workers were surprised to find that it had an ungulate skeleton.

 

[Crying Rock]

Note the robust tail, flexible spine, and yes, hooves. Early on, it was assumed that Pakicetus was just a primitive whale, based on the whale-like skull. Later, workers were surprised to find that it had an ungulate skeleton.

"...Note the robust tail, flexible spine, and yes, hooves..."

In one of your posts, no. Please show me a robust tail (outside of the ordinary for any land dwelling mammal), a flexible spine (outside of the ordinary for any land dwelling mammal), and yes, hooves.

This is what you have to work with:

http://www.edwardtbabinski.us/whales/ev ... fossil.gif

By the way, that's one sorry skull.

How do you work from that sorry skull, find fragmentary bones associated with it, and determine that your advancing your knowledge?

 

[lordkalvan]

^ Sigh. I think Barbarian's right: this is just a Gish Gallop, or perhaps a Hawkins' Hoedown.

ETA And what we 'have to work with' is already a great deal more than CR was aware of....

 

[Crying Rock]

http://www.edwardtbabinski.us/whales/ev ... fossil.gif[/url]

By the way, that's one sorry skull.

How do you work from that sorry skull, find fragmentary bones associated with it, and determine that your advancing your knowledge?[/quote:1w2zx403]

Please explain the evolutionary relationship between:

http://i291.photobucket.com/albums/ll31 ... eleton.jpg

And:

http://www.edwardtbabinski.us/whales/ev ... fossil.gif

 

[lordkalvan]

Please explain the evolutionary relationship between:

http://i291.photobucket.com/albums/ll31 ... eleton.jpg

And:

http://www.edwardtbabinski.us/whales/ev ... fossil.gif

Pakicetus and Indohyus are both artiodactyls. Like Pakicetus, Indohyus has morphological skull characteristics that are unique to cetaceans, although it is more generally regarded as an outgrouping from rather than an ancestor to whales. Together with confirming evidence from molecular phylogeny this and other evidence has been used to make a robust argument for combining Cetacea and Artiodactyla into a superorder called Cetartiodactyla.

 

[Barbarian]

Barbarian observes:
Note the robust tail, flexible spine, and yes, hooves. Early on, it was assumed that Pakicetus was just a primitive whale, based on the whale-like skull. Later, workers were surprised to find that it had an ungulate skeleton.

"...Note the robust tail, flexible spine, and yes, hooves..."

In one of your posts, no. Please show me a robust tail (outside of the ordinary for any land dwelling mammal)

Sure. Let's see how other ungulates are...
Horse tail:

bovine:

sheep:

Pakicetus:

Longer, more robust vertebrae. Like Ambulocetus.

Ungulates (such as the horse) have tended to go with a less flexible spine:
http://www.scienceofmotion.com/documents/preface.html

Pakicetus and other early whales had much more flex in the vertebrae:

Compare with that of a horse.

and yes, hooves.

The toes each had a keratinous hoof.
http://en.wikibooks.org/wiki/Anatomy_an ... s/The_Skin

This is what you have to work with:

http://www.edwardtbabinski.us/whales/ev ... fossil.gif

You're a little behind. There have been a number of Pakicetids discovered. Here's a better one:

Surprise.

 

[Crying Rock]

Barbarian observes:
Note the robust tail, flexible spine, and yes, hooves. Early on, it was assumed that Pakicetus was just a primitive whale, based on the whale-like skull. Later, workers were surprised to find that it had an ungulate skeleton.

"...Note the robust tail, flexible spine, and yes, hooves..."

In one of your posts, no. Please show me a robust tail (outside of the ordinary for any land dwelling mammal)

Sure. Let's see how other ungulates are...
Horse tail:

bovine:

sheep:

Pakicetus:

Longer, more robust vertebrae. Like Ambulocetus.

O.K., but we haven't got past a land dwelling mammal, and any sort of hard evidence that land dwelling mammals are the ancestors of marine dwelling mammals.

You must admit that the following tails are very dissimilar from horse, cow, sheep, and Pakicetus:

http://upload.wikimedia.org/wikipedia/c ... eleton.jpg

http://www.all-science-fair-projects.co ... eleton.jpg

http://photos.igougo.com/images/p168960 ... _Beach.jpg

http://upload.wikimedia.org/wikipedia/c ... eleton.png

 

[Barbarian]

(Barbarian demonstrates the primitive whale characteristics of Pakicetus and other primitive cetids)

O.K., but we haven't got past a land dwelling mammal, and any sort of hard evidence that land dwelling mammals are the ancestors of marine dwelling mammals. You must admit that the following tails are very dissimilar from horse, cow, sheep, and Pakicetus:

(skeletons of highly evolved modern whales)

Let's go a bit farther then...

Ambulocetus natans had tail vertebrae that were both long and robust, compared to those of horses, cows or sheep, but were not much bigger than those of Pakicetus. The tail, although robust, was still not the means of propulsion for Ambulocetus; it used a typical land animal "galloping" movement, using the large rear feet for propulsion. This is inferred from the large flipper-like feet, and the flexibility of the spine; it seems to have gotten about in water much as otters do.

Maicatetus inuus was a little farther along, and had a larger and more robust tail than Ambulocetids.

Rodhocetus had an even more robust tail, now probably quite useful in swimming; it was also more whale-like.

Dorudon is farther along, with an even bigger tail, and reduced hind legs. By now flukes were able to do propulsion, but the limits of evolution are still obvious; instead of the lateral undulation of fish, whales retain the land-based "galloping" movement to swim.

And then Basilosaurus:

Which is pretty much like modern whales:

 

[Crying Rock]

(Barbarian demonstrates the primitive whale characteristics of Pakicetus and other primitive cetids)

O.K., but we haven't got past a land dwelling mammal, and any sort of hard evidence that land dwelling mammals are the ancestors of marine dwelling mammals. You must admit that the following tails are very dissimilar from horse, cow, sheep, and Pakicetus:

Let's go a bit farther then...

Ambulocetus natans had tail vertebrae that were both long and robust, compared to those of horses, cows or sheep, but were not much bigger than those of Pakicetus. The tail, although robust, was still not the means of propulsion for Ambulocetus; it used a typical land animal "galloping" movement, using the large rear feet for propulsion. This is inferred from the large flipper-like feet, and the flexibility of the spine; it seems to have gotten about in water much as otters do.

And these these land dwelling mammals are your proof for an evolutionary relationship leading up to marine dwelling mammals? Can you demonstrate a solid evolutionary relationship between these land dwelling mammals. If not, then any subsequent suppositions crumble at their base.

 

[Barbarian]

And these these land dwelling mammals are your proof for an evolutionary relationship leading up to marine dwelling mammals?

As you see, they are just the start. The entire series of gradually more whale-like fossils shows how they evolved.

Can you demonstrate a solid evolutionary relationship between these land dwelling mammals.

Yep. The anatomical evidence quite nicely shows the relationship. And it solves a number of problems, such as "why do whales have horizontal flukes, instead of vertical fins?" The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates.

 

[Crying Rock]

And these these land dwelling mammals are your proof for an evolutionary relationship leading up to marine dwelling mammals?

As you see, they are just the start. The entire series of gradually more whale-like fossils shows how they evolved.

[quote:3yph453g]Can you demonstrate a solid evolutionary relationship between these land dwelling mammals.

Yep. The anatomical evidence quite nicely shows the relationship. And it solves a number of problems, such as "why do whales have horizontal flukes, instead of vertical fins?" The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates.[/quote:3yph453g]

"...Yep. The anatomical evidence quite nicely shows the relationship. And it solves a number of problems, such as "why do whales have horizontal flukes, instead of vertical fins?" The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates..."

And your argument is based on what: A bunch of fragmentary skeletons?

As a North American paleoarcheologist, I wouldn't dare to offer up your evidence as proof of anything.

Will you please offer up the peer reviewed dating techniques utilized on each of the land dwelling mammals we've discussed so far?

 

[Barbarian]

And your argument is based on what: A bunch of fragmentary skeletons?

A very large body of fossil evidence is available, as you just learned. But as compelling as it is, that isn't all there is.

We have, for example, the whale digestive system, which is an ungulate digestive system.

There is the DNA evidence, which gives us the same results; whales are descended from primitive ungulates.

There are isotope analyses of fossils, showing a transition from freshwater to marine life over time as whales became more and more dependent on the sea and less and less on the land.

There is even the solution to the question as to why whales swim with a "galloping" motion, like land animals.

As a North American paleoarcheologist, I wouldn't dare to offer up your evidence as proof of anything.

If so, you don't read your own discipline's literature. Here's a way to catch up:
http://www.masterdating.info/dating-met ... chaeology/

Will you please offer up the peer reviewed dating techniques utilized on each of the land dwelling mammals we've discussed so far?

Find out what Paleo-archeologists know, first, and we'll talk. Do you really not know how dating works?

 

[Crying Rock]

http://www.masterdating.info/dating-met ... chaeology/[/url]

Will you please offer up the peer reviewed dating techniques utilized on each of the land dwelling mammals we've discussed so far?

Find out what Paleo-archeologists know, first, and we'll talk. Do you really not know how dating works?[/quote:2i7ad60g][/quote:2i7ad60g]


Barb wrote:

“…Yep. The anatomical evidence quite nicely shows the relationship. And it solves a number of problems, such as "why do whales have horizontal flukes, instead of vertical fins?" The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates…â€

CR wrote:

“…And your argument is based on what: A bunch of fragmentary skeletons?

As a North American paleoarcheologist, I wouldn't dare to offer up your evidence as proof of anything.

Will you please offer up the peer reviewed dating techniques utilized on each of the land dwelling mammals we've discussed so far?..â€

Barb wrote:

“…If so, you don't read your own discipline's literature. Here's a way to catch up:
http://www.masterdating.info/dating-met ... chaeology/ …â€

CR wrote:

I’m quite aware of the various dating methods. Please answer my question: Will you please offer up the peer reviewed dating techniques utilized on each of the land dwelling mammals we've discussed so far?

Barb wrote:

“…The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates…â€

CR wrote:

And your physical evidence is? Imagination doesn’t count.

http://www.hedweb.com/animimag/horse-beach.htm

http://ecoles.cstrois-lacs.qc.ca/endl/a ... /whale.jpg

http://www.winteridgefarm.com/wandering ... umping.jpg

Barb wrote:

"...There is the DNA evidence, which gives us the same results; whales are descended from primitive ungulates..."

CR wrote:

Please offer up the nDNA sequences of primitive ungulates that prove whales descended from them.

Barb wrote:

"...There are isotope analyses of fossils, showing a transition from freshwater to marine life over time as whales became more and more dependent on the sea and less and less on the land..."

CR wrote:

Circular reasoning? Every land dwelling mammal drinks fresh water. Every ocean dwelling mammal is saturated with saltwater.

 

[lordkalvan]

Barb wrote:

"...There are isotope analyses of fossils, showing a transition from freshwater to marine life over time as whales became more and more dependent on the sea and less and less on the land..."

CR wrote:

Circular reasoning? Every land dwelling mammal drinks fresh water. Every ocean dwelling mammal is saturated with saltwater.

Lordkalvan wrote:

Huh?

 

[Barbarian]

Barbarian observes:
The reason is that whales evolved from animals that swam by a modification of the galloping motion found in ungulates…â€

And your physical evidence is?

http://www.jstor.org/pss/2401132

Watch films of them swimming. They use the same muscles as otters do swimming, which are the same muscles used by land animals galloping. Would you like some more detail?

Imagination doesn’t count.

But evidence does. And there it is.

 

[Barbarian]

Circular reasoning? Every land dwelling mammal drinks fresh water. Every ocean dwelling mammal is saturated with saltwater.

You have no idea what I'm talking about, do you?

Paleontologists believe that Pakicetus and other early cetaceans were furry, four-legged creatures that lived mostly on land, venturing into the water to feed on fish. According to current thinking, the earliest whales hunted in rivers and were unable to feed in salt water. Indeed, Pakicetus is found in river sediments, and the mixture of oxygen isotopes in its bones suggests it swam in fresh water.

The Indian fossil, however, came from marine sediments containing oysters and other ocean species, indicating that Himalayacetus swam in salt water. The ratio of oxygen isotopes in its bones supports this interpretation.

"Before, we might have thought that [these early whales] were restricted to fresh water, but here is a record from a marine environment," says Gingerich.

Despite its marine predilection, Himalayacetus apparently lacked key adaptations to aquatic life. Later whales developed enlarged canals in their lower jaws that improved their hearing underwater. Himalayacetus, though, had the small jaw canals of a land mammal, reports Gingerich. It appears that the Indian whale had already gained adaptations for feeding in salt water even though it could not hear well in that environment, he says.
http://www.thefreelibrary.com/Fossil+la ... a021237664

You, BTW, are also saturated in seawater.