The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World—and Us – Richard O. Prum

Thoughts: I found this one browsing the stacks at the Kitchener Public Library, and I’m glad I did: The Evolution of Beauty challenged my views on a subject I felt I knew a lot about and gave me lots of new ideas to think about. In it, Richard Prum argues (quite convincingly) that the idea of ornaments as honest signals neither fully nor accurately describes the process of sexual selection, and that arbitrary features can be selected for simply because other members of a species find those features to be aesthetically pleasing. It could have made a good pairing with / foil to Simler and Hanson’s The Elephant in the Brain as it touches on many of the same ideas, agreeing on several points but presenting contrary accounts on many more.

There’s a brief blurb on the back jacket taken from Elizabeth Kolbert’s review of the book: “Anyone interested in science or art or sex—which is to say everyone—will want to read it.” I could hardly agree more.

(The notes below are not a summary of the book, but rather raw notes - whatever I thought, at the time, might be worth remembering.)

Prum, Richard O. 2017. The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World—and Us. Doubleday.

Chapter 1: Darwin’s Really Dangerous Idea

• 22-23: Darwin presented the idea of sexual selection in his book The Descent of Man.
  • 23: “In the end, Descent was criticized by both creationist opponents of the very concept of evolution and fellow scientists who accepted natural selection but were adamantly opposed to sexual selection. To this day, Descent has never had the same intellectual impact as Origin.”
• 33: Alfred Russel Wallace “what is the first to propose the now exceedingly popular BioMatch.com hypothesis, which holds that all beauty provides a rich profile of practical information about the adaptive qualities of potential mates.”
  • “Today, most researchers agree with Wallace that all of sexual selection is simply a form of natural selection.” (this book, in contrast, argues that sexual selection is distinct from natural selection)
• 37: Ronald A. Fisher, based on a mathematical model, was one of the first to hypothesize that “a positive feedback loop between the sexual ornament and the meeting preference for the ornament will evolve through genetic covariation (that is, correlated genetic variation) between the two.”
  • 39: “What drives speculative market bubbles is desire itself. That is, something is desirable because it is desired, popular because it’s popular. Thus, Fisherian mate choice is the generic version of the ‘irrational exuberance’ of a market bubble.”
• 46: Amotz Zahavi “promoted the handicap principle with a single-minded fervor. But his idea had one big flaw. If the sexual advantage of an ornament is directly proportional to its survival costs, then the two forces will cancel each other out, and neither the costly ornament nor a mating preference for it can evolve. In a 1986 paper boldly titled”The Handicap Mechanism of Sexual Selection Does Not Work," Mark Kirkpatrick provided a mathematical proof of this evolutionarily trap."

Chapter 2: Beauty Happens

• 81-82: Beginning in the early 1990s, the idea that symmetry was an indicator of “good genes” was very popular in the scientific community.
  • 81: In the late 1990s, several papers critical of the idea came out. “by 1999, meta-analyses of multiple data sets showed that support for the idea had simply evaporated.”
  • 82: “The ‘honesty of symmetry’ has become a zombie idea—an idea so attractive that it lives on and on despite being repeatedly falsified.”

Chapter 3: Manakin Dances

Chapter 4: Aesthetic Innovation and Decadence

• 147: “the planar vane of the feather might have evolved through aesthetic selection to create a two dimensional canvas upon which to depict complex pigment patterns—including stripes, spots, thoughts, and spangles. The key innovation of the planar feather vane might have evolved because it provided a whole new way to be beautiful. ¶ This is a really big deal, because birds later evolved to use these same planar, vaned feathers to create aerodynamic forces required for flight. Feathers did not evolve for flight; rather, flight evolved from feathers. And among the best hypotheses for the key innovation that allowed birds to launch into the air is the desire for beauty.”

Chapter 5: Make Way for Duck Sex

Chapter 6: Beauty from the Beast

• 191-192: the extended phenotype: “the phrase communicates that an organism is more than the proteins created by the expression of its DNA, more even that its anatomy, its physiology, and its behavior. An organism’s complete phenotype includes all of the consequences of its genome’s interacting with its environment, including its impact on the environment. Thus, the beaver dam, which can create major changes to the ecosystem through the creation of pond that gradually silt in and become bogs, is part of the extended phenotype of the beaver.”
• 197: A study of Spotted Bowerbirds “found no support for the idea that the bower decorations that were favoured were rarer than any others.” (this in contrast to a statement made in The Elephant in the Brain, but perhaps that was looking at a different species)

Chapter 7: Bromance before Romance

Chapter 8: Human Beauty Happens Too

Chapter 9: Pleasure Happens

Chapter 10: The Lysistrata Effect

Chapter 11: The Queering of Homo sapiens

Chapter 12: The Aesthetic View of Life