A male flame bowerbird is a creature of incandescent beauty. The hue of his plumage transitions seamlessly from molten red to sunshine yellow. But that radiance is not enough to attract a mate. When males of most bowerbird species are ready to begin courting, they set about building the structure for which they are named: an assemblage of twigs shaped into a spire, corridor or hut. They decorate their bowers with scores of colorful objects, like flowers, berries, snail shells or, if they are near an urban area, bottle caps and plastic cutlery. Some bowerbirds even arrange the items in their collection from smallest to largest, forming a walkway that makes themselves and their trinkets all the more striking to a female — an optical illusion known as forced perspective that humans did not perfect until the 15th century.It's art, the scientists reason, and the development of such an elaborate courtship ritual is not adaptive. So why do they do it?
The way the theory works, of course, is that it's a kind of accident; natural selection doesn't necessarily mean that changes are useful, it just tends to strip away the ones that aren't via extinction. If the birds are 'good enough' at surviving in other ways, these kinds of extravagances can survive. But this is only one example; it turns out that nature seems to strive for beauty in many other ways.
It's a point Hannah Arendt made some years ago. She pointed out that animals are quite ugly internally -- intestines and the like -- but not externally. She reasoned that there was something about life that strives to be seen as beautiful. That's interesting, especially since so much of life lacks eyes that see; but even starfish are beautiful, in their way. In fact, it extends beyond life. Galaxies certainly are beautiful, and they're almost accidents. Waves on the ocean; sunsets.

