Sunday, September 5, 2010

Did Clothing Make Us Smarter?

I'm not talking here about looking smarter, asking you to "dress for success" or anything as superficial as that.  I'm wondering whether the evolutionary line leading to Homo sapiens got measurably smarter when bipedal former apes began to wear furs - a topic of serious scientific import.  The question arises out of a documentary on PBS the other night which traced the evolution of man's brain via the usual suspects - Australopithecus, Homo habilis, and all of our other well-known antecedents.  In fact Homo habilis is the brute upon which the question becomes sharply focused, because all of its bipedal ancestors had brains which for eons stayed virtually the same size.  H. habilis, however, was the first tool-maker and coincidentally had a larger brain case by almost 50%.  The question is "why the (relatively) sudden change"?  The PBS documentary wouldn't speculate, as I recall.  So I will.  As our ancestors moved northward out of Africa no doubt the chill of winter made clothes a good idea, and we do know that simple adaptation raises the temperature of the male genitalia several degrees centigrade, resulting in a vastly increased rate of sperm gene mutations.  Could this simple act of modesty have lead to "the great leap forward" in brain size?  Hmmm...