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To Shave a Cow: Sternberg on Whale Evolution

Photo: Pakicetus, by Kevin Guertin from Ottawa, Ontario, Canada, CC BY-SA 2.0 , via Wikimedia Commons.

Evolutionary biologist Richard Sternberg has some good lines in the brand new bonus video for the latest Science Uprising episode. He talks about the problem of evolving whales from the wolf- or greyhound-like Pakicetus, their presumed ancestor. That evolution, over a span of 11 million years or so, was once hailed as a “poster child” for the confirmation of Darwinian theory. Yet in a relatively small population, the bewildering variety of radical changes required for the transition from “walking whale” to the familiar, fully aquatic kind is, he says, roughly akin to reengineering your Volkswagen so as to be able to function as a submarine and explore the Marianas Trench. 

As Dr. Sternberg recounts (at 23:15), our colleague David Berlinski once estimated the number of required changes at 50,000. Sternberg from his own research thinks that may be a little on the high side but not by much: it would have to be 5,000 or 10,000 or more. There simply isn’t enough time, indicated by the fossil record, for all this to have been accomplished by unguided, unintelligent, uncoordinated, accident-based material processes alone. Remember, those forces would be lacking — crucially — any awareness or foresight as to the end goal. Sternberg offers a vivid image:

I would err on the side of David Berlinski’s estimate as opposed to those who think, well, all you’d have to do is shave a cow, cut off its legs, throw it in the water, and it would be able to perform the tasks of a whale; that is, only a few changes would have been required.

You would have to be very unkind to perform such an operation on a bovine. But as a thought experiment, it speaks for itself. The bonus video is from “Fossils: Mysterious Origins,” which you can see here now: