Credit: Marrabbio2There's a nice letter in Nature right now with an understated title, Mating advantage for rare males in wild guppy populations. But if you dig deeper you see some moderately grand claims being made.
The key issue is that the authors seem to be implying that negative frequency dependent selection (NFDS) is a major factor in maintaining genetic diversity in populations.
A reductio ad absurdum of the problem might be to ask why a superior and ideally fit morph does not dominate the whole planet? A more elaborated question lay at the heart of Charles Darwin's The Origin of Species. Fundamentally: why diversity? There have been many answers posited (e.g., see W. D. Hamilton's ideas in regards to sex, Narrow Roads of Gene Land). We needn't try to tackle the whole problem here, no matter what needs to be written in grant applications. Guppies are sufficient and interesting in ...
