Saturday, May 13, 2017

Wisdom Of The Week

The book in question, which publishes tomorrow, is The Evolution of Beauty: How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World—and Us. It’s a “natural history of beauty and desire”—a smorgasbord of evolutionary biology, philosophy, and sociology, filtered through Prum’s experiences as a birdwatcher and his diverse research on everything from dinosaur colors to duck sex. Through compelling arguments and colorful examples, Prum launches a counterstrike against the adaptationist regime, in an attempt to “put the subjective experience of animals back in the center of biology” and to “bring beauty back to the sciences.”

The central idea that animates the book is a longstanding one that Prum has rebranded as the “Beauty Happens hypothesis.” It starts with animals developing random preferences—for colors, songs, displays, and more—which they use in choosing their mates. Their offspring inherit not only those sexy traits, but also the preference for them. By choosing what they like, choosers transform both the form and the objects of their desires.

Critically, all of this is arbitrary—not adaptive. Songs and ornaments and dances evolve not because they signal good genes but because animals just like them. They’re not objectively informative; they’re subjectively pleasing. Beauty, in other words, just happens. “It’s a self-organizing process, by which selection will arrive at some standard of beauty all by itself, in the absence of any adaptive benefit—or, indeed, despite maladaptive disadvantage,” says Prum.

The originator of these ideas—Charles Darwin himself—suffered from similar problems. In The Descent of Man, he put forward an explicitly aesthetic view of sexual selection, in which animal beauty evolves because it’s pleasurable to the animals themselves. And despite the book’s title, Darwin spent many of its pages focusing on the choices of females, casting them as agents of their own evolution and arguing that their preferences were a powerful force behind nature’s diversity.

Darwin’s contemporaries were having none of it. They believed that animals didn’t have rich subjective worlds, lacking the mental abilities that had been divinely endowed to humans. And the idea of female animals making fine-grained choices seemed doubly preposterous to the Victorian patriarchy. One scientist wrote that female whims were so fickle that they could never act as a consistent source of selection. Alfred Russel Wallace, the co-discoverer of evolutionary theory, also rejected Darwin’s ideas, insisting that beauty must be the result of adaptation, and that sexual selection is just another form of natural selection. In a feat of sheer chutzpah, he even claimed that his view was more Darwinian than Darwin’s in a book called Darwinism. “I can still remember wanting to throw Wallace around the room when I read that,” says Prum, who accuses the man of turning sexual selection into an ‘intellectually impoverished theory.’”

That legacy still infects evolutionary biology today. Consider orgasms, which Prum does at length in a later chapter. “There’s an entire field on the evolution of orgasm that’s devoid of any discussion of pleasure,” he says. “It’s stunningly bad science, and once more, it places male quality at the causal center.” For example, some researchers suggested that contractions produced during female orgasm are adaptations that allow women to better “upsuck”—no, really—the sperm of the best males. Others theorists suggested that female orgasm is the equivalent of male nipples—an inconsequential byproduct of natural selection acting on the opposite sex. Both ideas trivialize the sexual agency of women, Prum says, and completely fail to engage with the thing they’re actually trying to explain--women’s subjective experiences of sexual pleasure.

His counter-explanation is simple: During human evolution, women preferred to have sex with men who stimulated their own sexual pleasure, leading to co-evolution between female desire and male behaviors that met those desires. That’s why, compared to our closest ape relatives, human sex is much longer, involves a variety of positions, and isn’t tied to fertility cycles. It’s also why female orgasm isn’t necessary for actual procreation. “It may be the greatest testament to the power of aesthetic evolution,” Prum writes. “It’s sexual pleasure for its own sake, which has evolved purely as a consequence of women’s pursuit of pleasure.”

- Review of new book The Evolution of Beauty: How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World—and Us by Richard Prum

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