Tuesday, February 03, 2009

Cheesecake and music: the products of sexual selection?

Pinker says that cheesecake and music are results of a large human brain that, though originally developed for other reasons, has free cycles to spend on creativity. Others have theories about how culture required the higher levels of cognition that a larger brain provides. Geoffrey's Miller The Mating Mind proposes and provides evidence for the theory that the human mind is a result of sexual selection, which Miller distinguishes from natural selection as a method in which the organisms themselves have agency in the traits that they propagate.

Miller's book provides a definition of sexual selection, proposes a theory of sexual selection through male competition and female choice, and provides many interesting evolutionary anecdotes. Though the introduction of the book is somewhat sensationalist, suggesting that this theory runs counter to everyone we've ever thought about, this book provides quite an interesting way to look at various traits as perpetuated because they are fitness markers rather than actually contributing to the fitness of an organism. A recurring example is that of the peacock's tail, which is costly to develop and maintain but could exist because a large, symmetric, and beautiful tail indicates that the peacock has been able to expend this extra energy despite environmental challenges. The book also talks about sexual differences and how they might arise: for instance, the more polygynous and organism is, the greater differences there are between male size and female size (because when it is winner-take-all, only the strongest males reproduce). Miller explains that the model of male competition and female choice exists because female eggs are the limiting and required resource for reproduction. As a result, we find much of the sexual ornamentation across organisms in the males. One reason Miller proposes for why there is not a great difference between the human brain in males and females is that the brain evolved not only through male competition but through female choice: in order to be sufficiently discerning, the female brain had to be able to distinguish a highly fit intellect from one that is less so.

I am not sure if I believe everything Miller says, but I recommend reading this book. The first reason I decided to read it is because I am always interested in theories about sexual differences between males and females, but the second reason is because the book got a positive endorsement from Richard Dawkins and generally good reviews about being "brilliantly written, "engaging," and that kind of thing. Even if you don't learn as much as I did, it is an intereseting and enjoyable read.

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