Beauty and the Rethinking of Evolution

How is evolution related to the beauty of animals? New scientific studies question some of natural selection’s most established criteria…

Nature knows nothing of the idea of ​​beauty. Inadvertently, though, it embodies beauty in all its splendor. From the plumage of a peacock, to the dances of birds of paradise and their striking nests, the survival of a species has its most powerful allies in its beauty and extravagance, in color and brilliance. This is perhaps true even in the world of humans. Science had shown that the evolution of a species, in its adaptive processes, is to be useful, to ensure that the individual keeps the species alive. But this is no longer an absolute truth. In a recent New York Times article, Ferris Jabr described how beauty as we understand it has transformed the way scientists are currently studying the evolution of species. Jabr discusses a new school of thought within evolutionary biology which puts into doubt many hypotheses which had until now remained absolute.

A tremendous number of species bear reproductive ornamentation which is metabolically costly, heavy, or simply difficult to carry around. Spiders have iridescent bellies, lizards carry enormous throats, and birds bear plumage of unthinkable color. These are just a few examples of steps that nature has taken to ensure that species survive. They also make scientists think that beauty in nature is, rather than mere decoration, part of a code.

According to the theory, ornamentation in certain animals is presented as a sign of positive qualities like good health, intelligence, and survival skill, and that these same characteristics can be passed on to offspring. Bright plumage, for example, can signify a robust immune system. In such a way, beauty is considered an aspect of natural selection.

For Darwin, the theorist and scholar of natural selection, beauty in animals didn’t necessarily reflect health or “good genes.” For Darwin, animals had aesthetic preferences, something he called “sexual selection.” The scientist dedicated several pages to this subject in his famous book The Descent of Man (1871). The theory was quickly ruled out by later scientists who argued, precisely, that beauty is synonymous of privileged genetics. More than a century later, new generations of biologists have returned to Darwin’s approach and argue that beauty isn’t necessarily an indicator of good health or favorable genes: it can be simply a genetic arbitrariness and thus, beauty in the animal kingdom may be one of the engines of evolution. Such thinking also supports the possibility that the aesthetic preferences of an animal may respond to psychological or environmental factors that have nothing to do with genetics or survival.

The new school of thought implies a rethinking not only of the evolution of beauty, but also of the way in which we conceive evolution itself. For decades, natural selection (the choice of reproductive partners determines the best genetic information) was thought to be a condition of genetic evolution. The new thought suggests that other forces are in play, forms of evolution that take into account an animal’s perception of the world surrounding it, and how its unique and individual way of perceiving that world decisively influences the physical appearance and behavior of the species. This raises the idea of two universes at play when we’re speaking of evolution: the outer physical world and an inner constructed universe.

Among this group of scientists, Richard Prum, an ornithologist at Yale University, stands out. Prum defends Darwinian theories of sexual selection in his 2017 book The Evolution of Beauty where he provides details of his own theories of evolution and aesthetics.

Prum’s studies, among those of many other scientists, pose a fascinating and inspiring reality: one of sophisticated perceptions in animals (perceptions henceforth unimagined) and a possibility that animals recognize a beauty we’re only beginning to understand.