Art Over Biology

The classic example is the peacock's tail. Why must an animal devote so much of its energy to producing a beautiful and decorative but ultimately nonfunctional tail? In a less enlightened time, such a feature would have been credited to a creator, but we no longer have it so easy. The question apparently plagued Darwin, who said, "The sight of a feather in the peacock’s tail, whenever I gaze at it, makes me sick." Like all things in an evolutionary Darwinian sense, it comes back to reproduction:

Animals produce beauty on their bodies; humans can also produce it in their artifacts. The natural inference, then, would be that art is a human form of sexual display, a way for males to impress females with spectacularly redundant creations. There is even an animal precedent for this: the Australian bowerbird, which attracts females by building an incredibly elaborate bower out of grass and twigs, and decorating it with colorful bits and the juice of crushed berries. The bower is a perfect example of an artwork whose explicit purpose is to promote reproduction.

Moreover:

In a strictly Darwinian nature, of course, there is no such thing as honor, value, or goodness; there is only success or failure at reproduction. But the very words “success” and “failure,” despite themselves, bring an emotive and ethical dimension into the discussion, so impossible is it for human beings to inhabit a valueless world....Likewise, it makes no sense logically for us to be emotionally invested in the question of whether or not art serves our evolutionary fitness. Still, there is an unmistakable sense in discussions of Darwinian aesthetics that by linking art to fitness, we can secure it against charges of irrelevance or frivolousness—that mattering to reproduction is what makes art, or anything, really matter.