Tag Archives: Sexual Selection

Sexual Selection Up To Date: A Taste for the Beautiful

A Taste for the Beautiful: The Evolution of Attraction is a popular science book written by an actual expert on the field, addressing the ways in which the world of animals is shaped by sexual selection.

One of Darwin’s major contributions to the panoply of theoretical and observational work we call “evolution” was to recognize, describe, and model sexual selection. Continue reading Sexual Selection Up To Date: A Taste for the Beautiful

Models of Sexual Selection

Darwin was puzzled by exaggerated traits. (Aren’t we all, really?) For example, why would a widow bird male have a tail so long that he could scarcely fly away from predators? Indeed, speaking of birds:

What a contrast is presented between the sexes by the polygamous peacock or pheasant, and the monogamous guinea-fowl or partridge! Many similar cases could be given, as in the grouse tribe, in which the males of the polygamous capercailzie and black-cock differ greatly from the females; whilst the sexes of the monogamous red grouse and ptarmigan differ very little. Amongst the Cursores, no great number of species offer strongly – marked sexual differences, except the bustards, and the great bustard (Otis tarda), is said to be polygamous. With the Grallatores, extremely few species differ sexually, but the ruff (Machetes pugnax) affords a strong exception, and this species is believed by Montagu to be a polygamist. Hence it appears that with birds there often exists a close relation between polygamy and the development of strongly-marked sexual differences. On asking Mr. Bartlett, at the Zoological Gardens, who has had such large experience with birds, whether the male tragopan (one of the Gallinaceæ) was polygamous, I was struck by his answering, “I do not know, but should think so from his splendid colours.”

Darwin, C. R. 1871. The descent of man, and selection in relation to sex. London: John Murray. Volume. 1. 1st edition. Pages 269-270

I don’t want to give a comprehensive (or bullet proof) “definition” of sexual selection. Instead, I want to lay out a few key ideas and suggest a way to think of models of sexual selection.

Darwinian Sexual Selection.
Females possess a built in aesthetic Continue reading Models of Sexual Selection