Sexual selection

Sexual selection is a special kind of natural selection. It is a theory of Charles Darwin that certain traits can be explained by competition within a species.

Darwin defined sexual selection as the effects of the "struggle between the individuals of one sex, generally the males, for the possession of the other sex".^[1] It is usually males who fight each other. Traits selected by male combat are called secondary sexual characteristics. They include horns, antlers, which are sometimes referred to as 'weapons'.

Traits selected by mate choice are called 'ornaments'. Females often prefer to mate with males with external ornaments – exaggerated features of morphology. Genes that enable males to develop impressive ornaments or fighting ability may simply show off greater disease resistance or a more efficient metabolism. This idea is known as the 'good genes' hypothesis. Sexual selection is still being researched and discussed today.^[2]

One author says studies on sexual selection have something important to tell us, namely "how males and females came to be what they are".^[3]

1. ↑ Darwin C. 1871. The Descent of Man and selection in relation to sex. John Murray, London.
2. ↑ Cronin, Helena 1991. The ant and the peacock: altruism and sexual selection from Darwin to today. Cambridge University Press.
3. ↑ Cite error: The named reference A&R was used but no text was provided for refs named (see the help page).