Sexual selection is a form of natural selection where one sex prefers a specific characteristic in an individual of the other sex. Peafowls exhibit sexual selection in that peahens look for peacocks with more "eyes" on their tail feathers.
Sexual selection can be thought of as two special kinds of natural selection, as described below. Natural selection occurs when some individuals out-reproduce others, and those that have more offspring differ genetically from those that have fewer.
On the writing of Descent, and Darwin's work on sexual selection in humans, see the Darwin Behind the Scenes virtual exhibit.. See also Darwin's correspondence with the doctor, John Beddoe, for Darwin's interest in the apparent increase in dark hair in the population of British women.
Jan 25, · Sexual selection is Darwin's second great insight, and he defined it as depending on “the advantage which certain individuals have over other individuals of the same sex and species solely in respect of reproduction”.So sexual selection can be thought of as intra-specific reproductive competition.