Last night, and again today at noon, I heard Joan Roughgarden speak. Although she is primarily known as a lizard ecologist, her current work is focused on a radical change in our evolutionary understanding of gender and sex. Contemporary understanding has changed very little since Darwin's coinage of the term "sexual selection": sexual relations are for the distribution of sperm, sperm are cheap and eggs are expensive so agressive males compete to win the right to mate with coy females, good genes are demonstrated by flashy plumage/bulging muscles and the flashiest/bulgiest gets to mate with the female.
Dr. Roughgarden's argument is that this is an oversimplification in most cases and simply wrong in others. Non-reproductive sex, both between and among male and females, occurs far too often in animals for sex to be thought of as merely procreative. In many species one or both genders have multiple strategies for attracting a mate. Very little research has been done to see if the beauty of the peacock's tail actually matters to the peahen.
She proposes changing the name of the theory from "sexual selection" to "social selection" reflecting her theory that fancy plumage and same-sex relations have a lot more to do with group hierarchy (which in turn could indirectly affect reproductive success). She also makes the point that very few evolutionary ecologists ever consider alternative hypotheses in these sorts of studies--for instance, they monitor changes in behavior of females when a male's tail feathers are trimmed but do not check to see if there are similar changes in the behavior of other males.
I don't know enough about this stuff to say much beyond I find it a fascinating idea, she's brave to propose a new theory, and I look forward to the studies examining her theory. _
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