I'm not sure if I buy Prum's idea - doesn't this just come down to 'hard-to-fake' signals?<p>I thought it was pretty well established already that there were both physical & behavioral 'adornments' that had no pragmatic use but signaled that the advertiser is so well-endowed they have energy to spare. And as far as beauty goes symmetry is hard to manufacture so also signals genetic fitness.<p>Lastly, don't mutations sometimes come along for the ride even if their benefit is negligible or even detrimental, as long as they don't tip the balance & prevent the genes being passed along?