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Evolution/Richard Sternberg and Whales

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Question
Greetings.

Richard Sternberg attempts to refute neo-Darwinism by looking at all the modifications that needed to happen to whales in a "short window of time".  He seems unconvinced that natural selection had enough "grist" for humpback whales to evolve from a Pakicetus considering population genetics.  How would you refute him, please?

Thank you.

For more information, 10 minutes of him discussing this is at the link below.
http://www.youtube.com/watch?v=KbAzZEu13_w

Answer
Dear Robert,

Well, his argument is interesting, and I'm glad he wasn't trying to invoke Intelligent Design or any other religious nonsense.  He does say very clearly that his ONLY problem with the idea of modern whales evolving from Pakicetus-like ancestors is that he doesn't think it was purely due to natural selection.  I can totally buy that.  I think there would have to be a very strong element of genetic drift involved, as well.

If you did have a very small population of proto-whales, it doesn't seem unlikely that they would rapidly become reproductively isolated from their terrestrial cousins if they started mating in the water.  You could consider this an example of peripatric speciation, where a subset of a larger population becomes reproductively isolated on the periphery of the range of the large, parent population because the isolated area is not conducive to survival or reproductive success in most of the members of the large, parent population.

I think that without invoking genetic drift, it's hard to make a case for whale evolution to happen so quickly.

But that's the rub:  I suspect that small population size *did* play a major role at the beginning of ancestral whales' divergence from their terrestrial ancestors.  And Sternberg doesn't argue against that.

Genetic drift probably plays a much bigger role in evolution than most people suspect.  Probably at least as important as natural selection.
All of this has an element of "Just So" to it.  All we can do is critically analyze the data (which I think Sternberg has), and be willing to modify our ideas when things don't quite "fit".

What thinkest thou?

:)

Dana  

Evolution

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Dana Krempels

Expertise

I can answer questions about evolutionary mechanisms and theory, including genetic drift, mutation, natural selection, etc. I also can clear up misconceptions about evolution as it's sometimes talked about by those not well-versed in the subject (e.g., some politicians and many religious fundamentalists).

Experience

I have a Ph.D. in Biology, and presently teach Evolution and Biodiversity, Genetics, Botany, and Zoology at the University of Miami.

Organizations
House Rabbit Society Beta Beta Beta Biological Honor Society

Publications
Exotic DVM Magazine (veterinary journal)

Education/Credentials
B.S. in Biology B.A. in English Ph.D. in Biology

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