[Blog post conceived and written by Kelly Zalocusky, Deisseroth lab] Since the writings of Charles Darwin, female sexual selection has been used to explain flashy-but-costly male traits, from the colorful dances of birds-of-paradise, to the boisterous song of tungara frogs, to the violent posturing of elephant seals. Today in PNAS, researchers from the State University of New York reveal that, at least when it comes to fruit fly pheromones, the effects of this sexual selection are bound by the limits of natural selection. After 7 generations, the prevalence of the gene for high levels of sexy pheromones increased in their mating population from 12% to 35% before hitting a bound and increasing no further. It seems there is a hard limit on the proportion of "sexy" males that can be sustained within a given population.
Happy Valentines Day.