The limitations of Sexual Selection

The guppies are a good example, because it's been demonstrated that increased predator pressure selects for less conspicuous guppies. Slevesque mentioned Joh Endler's experiments, which are summarised here. He stocked different experimental pools with different variations of guppies and different numbers of predators. In those with the most predators, the guppies with the drabbest colours were strongly selected for.Edited by caffeine, : No reason given.

And if a male is helping to raise the young, it's less helpful for him to be bright and colourful as well. Ensuring the young he's investing all this time and energy in do well is more important than picking up another lady.For other examples, see albatrosses, or Emperor penguins. both divide childcare equally, and males and females are pretty indistinguishable.I'm trying to find a more exhaustive look at this than the arbitrary examples we're coming up with, but all I keep coming across on the interwebs are statements that it's (generally speaking) true.ABE: So maybe the pattern isn't as tidy as I thought. I just found this article on sexual dimorphism on birds, which I don'd currently have the time to read in full. The abstract claims that, whilst size dimorphism follows the predicted pattern of correlating with differences in parental care, plumage-colour dimorphism doesn't. Essentially, it's correlated with whether or not males sleep around, which makes sense.Edited by caffeine, : No reason given.Edited by caffeine, : No reason given.