Of Cetaceans, hands, feet and convergence
Zachriel has posted the claim that cetaceans have hands. I have questioned that claim, and for a very good reason. Not one of the alleged ancestors had hands!
However hands could (on a cetacean) develop via convergence. Ooops but that would be a point for me so we know Zachriel will deny it. So then he would have to deny that cetaceans have hands.
Then we have cetaceans with feet. I guess it they were hooved feet one would make the connection to its alleged land ancestors. And what is it that allowed everything else to get bigger, but the hindlimbs all but disappear?
As for the new dolphin find- dolphins do have information for fins. A mutation occurred that copied that existing information and placed those fins on another section of the body. We have seen this sort of thing with fruit flies- extra wings and legs out-of-place.
From living organisms we know, because we observe, that similarity in bone structure can in reality lead to very different forms once the rest of the structure is represented. Therefore any represenation of an organism in which only fossilized bone is present, which appears to go against that norm, should be taken for what it is- a biased opinion.
And to top it all off I again offer the following which I would say that convergnce is musch more common than Zachriel and his ilk will admit:
Unified physics theory explains animals' running, flying and swimming
However hands could (on a cetacean) develop via convergence. Ooops but that would be a point for me so we know Zachriel will deny it. So then he would have to deny that cetaceans have hands.
Then we have cetaceans with feet. I guess it they were hooved feet one would make the connection to its alleged land ancestors. And what is it that allowed everything else to get bigger, but the hindlimbs all but disappear?
As for the new dolphin find- dolphins do have information for fins. A mutation occurred that copied that existing information and placed those fins on another section of the body. We have seen this sort of thing with fruit flies- extra wings and legs out-of-place.
From living organisms we know, because we observe, that similarity in bone structure can in reality lead to very different forms once the rest of the structure is represented. Therefore any represenation of an organism in which only fossilized bone is present, which appears to go against that norm, should be taken for what it is- a biased opinion.
And to top it all off I again offer the following which I would say that convergnce is musch more common than Zachriel and his ilk will admit:
Unified physics theory explains animals' running, flying and swimming
The findings may have implications for understanding animal evolution, Marden said. One view of evolution holds that it is not a purely deterministic process; that history is full of chance and historical contingency. It is the idea purported by Steven Jay Gould and others that if you were to "rewind the tape" and run it again, evolution would proceed down a different path, Marden said.
"Our finding that animal locomotion adheres to constructal theory tells us that -- even though you couldn't predict exactly what animals would look like if you started evolution over on earth, or it happened on another planet -- with a given gravity and density of their tissues, the same basic patterns of their design would evolve again," Marden said.
10 Comments:
At 2:35 PM, Zachriel said…
joe g: "Not one of the alleged ancestors had hands!"
Journal Science: Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan
Protocetidae is a family of the order Cetacea.
At 2:43 PM, Zachriel said…
joe g: " A mutation occurred that copied that existing information and placed those fins on another section of the body."
Huh? As dolphin embryos have hind-limb buds, it seems much more likely that the extra fins are related to those structures. The find is not unique, by the way, just rare. Your claim is testable, though, and will be tested.
"Our finding that animal locomotion adheres to constructal theory tells us that -- even though you couldn't predict exactly what animals would look like if you started evolution over on earth, or it happened on another planet -- with a given gravity and density of their tissues, the same basic patterns of their design would evolve again," Marden said."
I agree.
At 7:37 AM, Joe G said…
Zachriel,
Ceataceans allegedly evolved from hooved land mammals. Last I checked hooves are NOT hands.
I know what your link sez but reality refutes your scientists yet again. IOW they are saying "hands and feet" because that is what the fossilized remains "look like". However as I stated in my OP without the fleshy parts only people with strong ore-conceived bias (and little common sense) would call those structures "hands or feet".
Then there is convergence...
At 7:39 AM, Joe G said…
joe g: " A mutation occurred that copied that existing information and placed those fins on another section of the body."
Zachriel:
Huh? As dolphin embryos have hind-limb buds, it seems much more likely that the extra fins are related to those structures. The find is not unique, by the way, just rare. Your claim is testable, though, and will be tested.
Unlike your claim of common descent which will never be objectively tested.
At 2:28 PM, Zachriel said…
Joe G: "Last I checked hooves are NOT hands."
Try not to get bogged down in semantics. The structures of all vertebrates have specific points of comparision. In fact, they show a nested hierarchy of such structures.
At 9:10 PM, Zachriel said…
I have been considering the question in more detail.
All mammals have analogous structures. These includes vertebrae, cranium, ribs, sternum, lungs, heart, hair, limbs with digits, and so on.
A 'true hand' is only found in primates, such as humans. However, 'hand' is often used to distinguish the forelimb paw or foot from the rearlimb paw or foot. No one claims that an ancient cetacean had the hand of a primate. Rather they had structures predicted to be homologous with other mammals, and these predictions have been validated.
There is no other way to rationally read the cites provided. The difference in usage can be easily determined from context, so I'm not really sure the root of your confusion.
At 8:13 AM, Joe G said…
Joe G: "Last I checked hooves are NOT hands."
Zachriel:
Try not to get bogged down in semantics.
It's reality, not semantics, at work here.
Zachriel:
The structures of all vertebrates have specific points of comparision.
That doesn't make a hoof a hand.
Zachriel:
In fact, they show a nested hierarchy of such structures.
As well they should, seeing they have a common design.
At 8:16 AM, Joe G said…
ZAchriel:
No one claims that an ancient cetacean had the hand of a primate. Rather they had structures predicted to be homologous with other mammals, and these predictions have been validated.
Apparently you don't understand homology. Similarity isn't enough. Homology means derived from a common ancestor. Do not confuse homology with homoplasy.
And under a common design scenario and given the physics paper I linked to, I would expect quite a bit of homoplasy. I would also expect evos to conflate the two in order to deceptively try to bolster their claims.
At 9:39 AM, Zachriel said…
joe g: "It's reality, not semantics, at work here."
As scientists sometimes use the word "hand" to refer to the digits and related structures of a forelimb in any tetrapod, including Cetaceans, then your previous assertions in this regard are false. I have provided a variety of cites, and even a dictionary definition.
Please try to deal honestly with this issue of terminology. That way when we discuss scientific papers, we won't conflate the intent of the authors. For instance, in Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan, the authors use the terminology "hands and feet" in the title, but include a much more detailed and technical analysis of the limb structures within the body of the article. This way you shouldn't be confused.
hands, the forelimb segment (as the terminal section of a bird's wing) of a vertebrate higher than the fishes that corresponds to the hand irrespective of its form or functional specialization.
At 11:06 AM, Joe G said…
Thanks for the definition as it proves my point. The limbs of whales should correspond to the hooves of their alleged ancestors.
That the structures in question resemble "hands" in the minds of many people, including those scientists you cite, is a clear example of what CONVERGENCE can do. It is also great evidence of what minds are capable of imagining.
Post a Comment
<< Home