Promiscuity: An Evolutionary History of Sperm Competition

by Tim Birkhead

Males are promiscuous and ferociously competitive. Females--both human and of other species--are naturally monogamous. That at least is what the study of sexual behavior after Darwin assumed, perhaps because it was written by men. Only in recent years has this version of events been challenged. Females, it has become clear, are remarkably promiscuous and have evolved an astonishing array of strategies, employed both before and after copulation, to determine exactly who will father their offspring. 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. Lucidly written and lavishly illustrated, with a wealth of fascinating detail and vivid examples, Promiscuity is the ultimate guide to the battle of the sexes.

Genres: Science, Biology, Nonfiction, Evolution, Nature, Psychology, Sexuality

292 pages, Paperback

First published May 2, 2000

About the author

Tim Birkhead is an award-winning author and one of the world’s leading bird biologists. He is the coauthor of Ten Thousand Birds: Ornithology since Darwin (Princeton) and the author of The Wonderful Mr. Willughby: The First True Ornithologist, The Most Perfect Thing: The Inside (and Outside) of a Bird’s Egg, and Bird Sense: What It’s Like to Be a Bird, among other books. He is a Fellow of the Royal Society and professor emeritus of zoology at the University of Sheffield.

Reviews

[Makomai]

"Ancora da studente, a Bristol, Parker era stato incoraggiato a studiare il comportamento del tafano giallo dall’importante entomologo Howard Hinton. Com’era fatto comune per gli studenti migliori di quei tempi cosi’ eccitanti, Parker venne convinto a proseguire il proprio lavoro per la laurea, sempre sotto la supervisione di Hinton. Una volta trascorso un anno di studio ateleologico, Parker si rese conto che se avesse voluto ottenere un qualsiasi risultato significativo avrebbe dovuto porre delle domande specifiche. Dopo aver passato diversi mesi con il naso a pochi centimetri da piccole zolle di sterco di vacca, osservando l’intensa competizione tra i maschi di tafano per le femmine, Parker penso’ che il problema verso cui si sarebbe dovuto rivolgere era la selezione sessuale, e specificamente la competizione tra maschi. Lo scenario era questo: una femmina di tafano arriva al mucchietto di sterco pronta per copulare ed e’ poi quasi immediatamente in grado di rilasciare le proprie uova sulla superficie dell’escremento. Non deve attendere a lungo: non appena arrivata, subito viene acchiappata da un maschio che istantaneamente copula con lei. Prima che lui abbia finito, un maschio piu’ grosso afferra i due, allontana il primo maschio dalla femmina, se ne libera e copula a sua volta. La faccenda si ripete incessantemente sotto gli occhi di Parker, ora dopo ora, giorno dopo giorno, su ogni mucchietto di sterco fresco."

Questa e’ la scienza: piena di merda, ripetitiva e soprattutto indeterminata tanto sul risultato (anche incertum an) quanto sulla direzione.

Questi sono i veri eroi.