Nature's Nether Regions: What the Sex Lives of Bugs, Birds, and Beasts Tell Us About Evolution, Biodiversity, and Ourselves
Menno Schilthuizen
Language: English
Pages: 197
ISBN: 2:00323717
Format: PDF / Kindle (mobi) / ePub
A tour of evolution's most inventive—and essential—creations: animal genitalia
Forget opposable thumbs and canine teeth: the largest anatomical differences between humans and chimps are found below the belt. In Nature's Nether Regions, ecologist and evolutionary biologist Menno Schilthuizen invites readers to discover the wondrous diversity of animalian reproductive organs. Schilthuizen packs this delightful read with astonishing scientific insights while maintaining an absorbing narrative style reminiscent of Mary Roach and Jerry Coyne. With illustrations throughout and vivid field anecdotes—among them laser surgery on a fruit fly's privates and a snail orgy—Nature's Nether Regions is a celebration of life in all shapes and sizes.
“Allohormones and Sensory Traps: A Fundamental Difference Between Hermaphrodites and Gonochorists?” Invertebrate Reproduction and Development 48:101–7. Koene, J. M., and R. Chase. 1998a. “The Love Dart of Helix aspersa Müller Is Not a Gift of Calcium.” Journal of Molluscan Studies 64:75–80. Koene, J. M., and R. Chase. 1998b. “Changes in the Reproductive System of the Snail Helix aspersa Caused by Mucus from the Love Dart.” Journal of Experimental Biology 201:2313–19. Koene, J. M.,
scooted along the thread at a speed of less than 3 centimeters (1 inch) per second, whereas half-emasculated males did so at more than 4 centimeters (1.5 inch) per second. Not only that, their endurance was also severely affected by the presence of an extra pedipalp. The researchers used a small paintbrush to chase a male around a piece of paper. If the male still had both pedipalps, he would collapse from exhaustion after about twenty minutes, whereas males that had self-amputated one pedipalp
particularly nasty ejaculate would still reap reproductive benefits. On the female side, however, there is also something going on. In seed beetles, which likewise fill their ejaculates with female-unfriendly substances, some females have more genetic immunity to the toxic effects than others. With male genes that make semen proteins differ in their toxicity, and female genes that cause variation in how susceptible a female will be, the stage is set for rapidly spiraling evolution, in which
particularly vicious genitalia. We have already come across a fair bit of traumatic insemination and harmful genitals in gonochoristic animals. Those examples pale in comparison to what is considered normal in the hermaphrodite realm. There are several reasons why hermaphrodite genital evolution has been taken to such extremes, according to Koene. You have to realize that for, say, a male insect to manipulate the reproductive system of a female, evolution has had to “invent” substances that
while the penis sizes of these two species were respectable, they never approached the lengths claimed by Redi. So, with the advancing knowledge of Limax coitus, Redi’s observations began to sound more and more ridiculous, and by the early twentieth century H. Wallis Kew dismissed them as “quite obscure.” Surely, Redi must have exaggerated the priapic prowess of his Latin slugs! Either that or he had mistaken slime threads for penises. But in the first few decades of the twentieth century, as