A peacock, which made Darwin “sick.” Photo by aussiegal.

This week at the collaborative blog Nothing in Biology Makes Sense!, guest contributor Tom Houslay makes sense of costly mating displays:

Time and again in the animal kingdom, we see exaggerated ornaments, vibrant colours, and fantastic acoustic and visual displays. Frogs and crickets advertise their whereabouts with loud calls, fireflies flash patterns with bioluminescence; greater sage grouse strut brazenly in open pastures. While they undoubtedly brighten up the world around us, these behaviours and morphologies can seem not only unnecessary, but downright detrimental to the survival of an individual. How, then, can their existence be resolved with our knowledge of evolution?

To find out how a single showy trait can come to “capture” all the genetic variation in a population, read the whole thing. On an almost totally unrelated note: if I ever open a gay bar, it will definitely be called Lek. ◼