Fisherian runaway: Difference between revisions

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 [[maladaptiveness|maladaptive]] and the species died out.