Another must-read! Either I am not discriminating enough, I don’t read enough, or terrific books are more common (I unsurprisingly favor the latter interpretation).
I first heard about Richard Prum when he gave the talk at one of the annual Darwin’s Day Dinners* in Norwalk, CT, where we lived until late 2017. He gave a terrific presentation, but it didn’t quite register with me how revolutionary his ideas were. I had read Darwin’s second major book on Evolution, “The Descent of Man, and Selection in Relation to Sex,” and had internalized the notion of sexual selection in a dim way, so Prum’s featuring it was not surprising. Prum calls it “Darwin’s really dangerous idea,” a reference to Daniel Dennett’s book “Darwin’s Dangerous Idea,” about natural selection.
Alfred Russel Wallace famously came up with the idea of natural selection independently and sent Darwin a letter outlining his theory. This galvanized Darwin to finish his book, which he had been reluctant to publish. Wallace was younger than Darwin, and had not spent the years of intense thought and field research that gave Darwin’s theory such depth and explanatory power. Far from feeling resentful that natural selection had become “Darwin’s theory,” he was an enthusiastic promoter of Darwin. But he was also deeply religious, unlike the agnostic, growing on atheistic, Darwin.
When “Descent of Man” was published in 1871, 12 years after “Origin,” it was brutally attacked for a variety of reasons described by Prum. It was just too much for a Victorian readership. Wallace was scandalized, feeling that Darwin had betrayed his own theory and feeling that the book undermined his religious beliefs. Wallace subsequently did such a thorough job of trashing the idea of sexual selection based on aesthetic choice that it was basically ignored for 140 years.
Instead, there grew the notion, embedded in nearly all research to the present and parroted in every book on evolution I have read, that traits were either adaptive (fit to the animal’s environment), neutral, or the secondary result of adaptive traits. In my extensive thinking about the origins of art, I have gone along with the herd, searching for some reason why art would be adaptive. That’s why this book was so revealing to me, because it opened the door to other ways art might have evolved. I hope to parse the implications in the near future.
I had not registered the extent to which adaptationism had permeated the field of evolutionary studies until I read Prum’s book. I happened to reread the section on art in Steven Pinker’s book “How the Mind Works” and it was now clear to me why he had famously dismissed art as a form of sensory “cheesecake:” he couldn’t envision how pleasure could be the basis for the evolution of art. Prum bars no holds in his scorn of stubborn adaptationists like Pinker and Richard Dawkins. He also convincingly debunks many notions that have made it into the popular press, such as the idea that men have evolved to prefer hourglass figures, symmetrical features, and features that are an averaged composite, all of which have been thoroughly disproved. He particularly attacks the tired notion that fancy plumage is an indication of fitness, another attempt by adaptationists to explain beauty in nature.
The meat of Prum’s book are his wonderful descriptions of the behavior of tropical birds – he is a master ornithologist who has spent much time studying birds in tropical forests around the world (deafness has reduced his field work). Of particular interest is his discussion of the details of sexual anatomy and mating behavior in ducks (which have penises, unlike 95% of birds). Later in the book he applies his insights to human beauty, and particularly to how sexual selection is the likely source for the exaggerated sexual ornaments and behavior in humans. This is worth reading regardless of your interest in the details of evolution.
Throughout he relates his findings to female empowerment by means of sexual selection. He is careful to distinguish female power through choice from female domination, which is nowhere found. Prum makes the depressing conjecture that prior to the evolution of agricultural civilization women had “domesticated” men and established a substantial amount of female control through choice, only to have this control almost completely undermined by the evolution of paternalistic hierarchies.
Prum is always careful to distinguish solid fact and observation from speculation, and to note that many of his fruitful ideas need to be verified by further research.
This is a beautifully written book full of visual delight and descriptions of nature at her most lavishly creative. Most of all, it dramatically expands the horizons of evolution. Along with “evo-devo” and horizontal gene transfer among prokaryotes, sexual selection reduces the need to burden natural selection with carrying the entire load of explaining how and why organisms are as they are.
- The celebration in Norwalk is among a very short list of celebrations of Darwin’s birthday, and it is truly wonderful, bringing together intellectually curious people who might not otherwise meet each other. There is a science quiz that is quite sophisticated, with various tables of 10 competing. Ours never won, but we placed a couple of years. I hope some day that such celebrations become commonplace. See the Wikipedia entry on “Darwin Day.”