Fisherian runaway: Difference between revisions

Another mechanism that could explain exaggerated ornament and the immense sexual attraction to it, could be [https://en.wikipedia.org/wiki/Handicap_principle Zahavi's handicap principle], also called ''good genes hypothesis'' which claims that exaggerated ornament is a costly and hence reliable signal of other desirable traits. For example, a peacock with a very large tail would be easy prey (which is costly), hence must likely have other good traits that make up for it enabling his survival despite his handicap (good genes).  There is, however, little supporting scientific evidence.  In humans in particular, beauty is not strongly correlated with health at all, and even less with cognitive ability.<ref>https://incels.wiki/w/Scientific_Blackpill#Attractive_people_are_perceived_much_more_positively_than_they_really_are</ref> Neither does human ornament like seem to be particularly costly (except for tallness and large female breasts).

For example, in peafowls, the males evolved to have extremely large plumage, most likely due to persistent female preference for large plumage, strengthened by Fisherian runaway.  The preference the peahens have for large plumage caused the peacock's plumage to become absurdly large, hindering its mobility to evade predators, and also requiring a lot of energy to grow and maintain.

It has been hypothesized that Fisherian runaway selection contributed to the demise of the Sabre-tooth Tiger, by which female Sabre-tooths preference for males with long fangs resulted in a Fisherian runaway occurring, which led to the tiger's teeth becoming so large they became a liability, hampering the beasts ability to feed itself, and most likely led to frequent infections from the brittle, comically large teeth breaking.

The Irish elk is known to have gone extinct from female selection giving way to Fisherian runaway.  The female Irish elk preferred male Irish elk with large horns.  Eventually this preference created a feedback loop that resulted in Irish elk eventually evolving to carry 3.6 meter wide horns, one meter longer than its height.  Energy requirements for Irish elk antler growth were 75% as large as the energy requirements for fat and protein deposition. The enormous amount of calcium required to grow the antlers resulted the calcium being depleted from most of the body causing a state like similar to osteoporosis.  The adaptive trait in Irish elk became [[maladaptive]] and the species died out.