Promiscuity: An Evolutionary History of Sperm Competition

Rating:
Summary: Stranger-than-fiction sex book
Review: "Promiscuity" is about sex. Well, I suppose that much is obvious. And sex always makes for great reading. We are all obsessed and entertained by it. Still, this book took me by surprise. It is not your typical book about sex: offering cheap thrills or mundane, overdigested sociopsychological chatter. It is a unique guided tour of the bizarre world of reproduction throughout the animal kingdom. It is also a glimpse into the odd world of evolutionary biologists, in this case those who spend their lives contemplating the meaning behind all of the bizarre variations on sex in the animal world. Apparently, these highly respected academic scholars go to work each day to figure out such things as why some fruitflies make sperm that are 20 times longer than their bodies and why others produce seminal fluids that are toxic to their mates, why some marine flatworms have dozens of penises, why certain slugs have a penis that is longer than their body and that occassionally become so horrifically tangled about their mate that they must be chewed off, why dunglfies sometimes drown their mates in wet dung, why females of one species of catfish fertilize their eggs by drinking sperm, and why deep-sea anglerfish males bite their mates and never let go. The list goes on and on, preparing me with remarkable ammunition for the next dinner party.

Yet this stranger-than-fiction book is not merely a collection of Ripley's sex tales. It is a well-organized treatise of cutting edge science that masterfully instructs the reader as to the common evolutionary threads that define the underlying nature of sex. The reader is left, for example, with an abundant understanding of why sex between men and women is more about conflict than cooperation, which personally clarified much in my life. The first paragraph of the book reads in part, "Status for the Mediterranean male is all-important, and tradition dictates that a man who fails during a hunting expedition can expect his wife to be unfaithful. In parts of Italy it is widely believed that a man must shoot a honey buzzard each year if his wife is to remain faithful. So strong is this belief, and so powerful a motivating force is the idea of female fidelity, that even after they have emigrated to the United States many Italian men return home each year to shoot a honey buzzard. It is not a little ironic that in order to fulfil this ritual a man usually leaves his wife behind. Moreover, in some instances it is the wife who actually encourages him to go!" The remainder of the pages are as engaging as this first one. I recommend this book to anyone that ever has had or ever hopes to have sex.

Rating:
Summary: a test to reach easter
Review: If you want to be grossed out, amused and steeped in leading scholarship all at the same time, this may be your book. In a fun, concise and well structured book, Birkhead gives us an up-to-date account of sperm competition in animals. The examples used are wide-ranging, from bed bugs to people, and never fail to raise an eyebrow. A Doay sheep female copulated 163 times in five hours and a man eating sushi once learned that the wiggly things in his tongue owed their thanks to a squid spermatophore. Beyond these exemplars of bizarre, though, this book contains cogent arguments for the place of sperm competition. It kindly sandbags the sensational claims of Baker and Bellis (in their Human Sperm Competition), giving us a fairer treatment in its place, both with respect to humans (where sperm competition has been of relatively little recent importance, evidenced by the relatively small testes and poor sperm quality of males) and numerous other taxa. The section on female benefits to multi-male mating is also worth noting. Evidence is amassed for female benefits in obtaining sufficient sperm, resources and improving the genetic quality of their offspring (e.g. through pairing her genes with a good MHC complement). These last ideas on genetic benefits will continue to inspire new research, just as other ideas in the book should too (accessory glands such as the prostate may have originated in the evolutionary battle of the sexes). It could be stated that the book overstates the case for sexual conflict, when benign agreements have been reached; after all, it wouldn't pay over evolutionary time for the faithful California mouse or swan to employ cruel mechanisms at expense to a partner. Yet this book is worth the strange questions and looks you'll get on the bus when people see its cover and look over your should while reading it (just as happened to my yesterday).