Competition evolutionary history sperm

Tim Birkhead reveals a wonderful world in which males and females vie with each other as they strive to maximize their reproductive success. Both sexes have evolved staggeringly sophisticated ways to get what they want--often at the expense of the other. He introduces us to fish whose first encounter locks them together for life in a perpetual sexual embrace; hermaphrodites who "joust" with their reproductive organs, each trying to inseminate the other without being inseminated; and tiny flies whose seminal fluid is so toxic that it not only destroys the sperm of rival males but eventually kills the female. He explores the long and tortuous road leading to our current state of knowledge, from Aristotle's observations on chickens, to the first successful artificial insemination in the seventeenth century, to today's ingenious molecular markers for assigning paternity. And he shows how much human behavior--from the wife-sharing habits of Inuit hunters to Charlie Chaplin's paternity case--is influenced by sperm competition.

Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg [1] during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase males' chance of reproductive success.

Birkhead , Trade Paperback. There may be underlining, highlighting, and or writing. May not include supplemental items like discs, access codes, dust jacket, etc. Will be a good Reading copy. Females--both human and of other species--are naturally monogamous.

Sperm competition theory assumes a trade-off between precopulatory traits that increase mating success and postcopulatory traits that increase fertilization success. Predictions for how sperm competition might affect male expenditure on these traits depend on the number of competing males, the advantage gained from expenditure on weapons, and the level of sperm competition. However, empirical tests of sperm competition theory rarely examine precopulatory male expenditure.