What's the easiest way to tell species apart? Check their genitals. Researching private parts was long considered taboo, but scientists are now beginning to understand that the wild diversity of sex organs across species can tell us a lot about evolution.
Menno Schilthuizen invites readers to join him as he uncovers the ways the shapes and functions of genitalia have been molded by complex Darwinian struggles: penises that have lost their spines but evolved appendages to displace sperm; female orgasms that select or reject semen from males, in turn subtly modifying the females' genital shape. We learn why spiders masturbate into miniature webs, discover she-dungflies that store sperm from attractive males in their bellies, and see how, when it comes to outlandish appendages and bizarre behaviors, humans are downright boring.
Nature's Nether Regions joyfully demonstrates that the more we learn about the multiform private parts of animals, the more we understand our own unique place in the great diversity of life.
"Schilthuizen whizzes between geographies and species, learning from apes, slugs, spiders. In the process he invites us on all kinds of interesting adventures, from finding ancient beetle genitals trapped in amber to examining barnacles depositing their sperm with eight-foot-long appendages [...] This is a book about heterosexual sex between animals, but Schilthuizen hasn't closed the case on other kinds of sex driving animal evolution, too. Ever excited, ever open-minded, he pushes towards new frontiers."
– Tess Taylor, Barnes and Nobles Review
"From the very first page, Menno Schilthuizen makes us both laugh and think about the bewildering genital variation in the animal kingdom. We laugh at the outrageous shapes these organs take, and think about the central issue of this book: how genital anatomy advances male and female procreation. An exhilarating and most informative read!"
– Frans de Waal, author of The Bonobo and the Atheist
"A remarkable book [...] succeeds in finding exactly the right tone [...] . Schilthuizen's entertaining work reminds us not to take 'the mechanics of sexual intercourse' for granted.'"
– Publishers Weekly
"A provocative voyage on the 'vast ocean of sexual function beyond the quiet backwater that we humans find ourselves in.'"
"The science of genitals is a relatively new field for biologists, who have long overlooked the evolutionary importance of species' private parts. Biologist Schilthuizen balances the silly and the serious to describe researchers' latest efforts to understand how 'evolution has graced the animal kingdom with such a bewildering diversity of reproductive organs.' Schilthuizen tours some of nature's weirdest inventions, such as the chicken flea penis, which is 'actually a profusion of plates, combs, springs, and levers' and looks like 'an exploded grandfather clock.'"
– Scientific American
"Rather than furiously flipping through a stack of increasingly obscure science journals, those interested now have an easily digestible text to work with, the charmingly titled, Nature's Nether Regions, by Dutch evolutionary biologist Menno Schilthuizen. Menno's book is a deep dive into the science of genitals, one that comes interspersed with a selection of the finest, and most scientifically-accurate, sex jokes."
– Lex Berko, Vice's Motherboard
"A closer look between the legs (or, in the case of the Australian velvet worm, on the head) to explore what the sex lives of various creatures can teach us about reproduction, diversity and human sexuality [...] . I actually missed my stop on the train this morning because I was engrossed in the chapter about duck sex."
– Lindsay Abrams, Salon