Evolution Used the Same Molecular Toolkit? Common Sense from Jonathan Marks

“Every time I see a thoughtless headline like this one at Science Daily, “Evolution Used Similar Molecular Toolkits to Shape Flies, Worms, and Humans,” where the organisms being compared are as different (morphologically) as flies, worms, and humans, I think of Jonathan Marks’s blunt comment.

Marks is an evolutionary biologist/anthropologist at the University of North Carolina, and an uncommonly plain speaker and writer (bless him). In a 1993 talk to the American Association for the Advancement of Science in Boston, which I attended as a graduate student and will never forget, he said the following:

If the overall biology of the animals tells you that they are very different, and the genetics tells you that they are nearly identical, it follows that the genetic comparison is telling you something relatively trivial about the overall biology.

See also his paper “What Is the Viewpoint of Hemoglobin, and Does It Matter?” in the journalHistory and Philosophy of the Life Sciences. Considering “reductive trends in evolutionary anthropology,” he writes there (p. 245):

Does it not stand to reason that if you essentially cannot tell human hemoglobin from gorilla hemoglobin, the sensible thing to do is to look at something else? In other words, if you cannot tell a human from a gorilla, you really should not be in biology.

And:

If hemoglobin provides you with a lens that blurs the difference between human and gorilla, then just get a different lens. What is curious is why anyone would want to privilege such a weird dataset, a dataset that makes a human seem like a gorilla.”

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#evolution, #id, #molecular, #science