Genitals are an important part of our daily lives. They complete the digestive process, they help bring us pleasure and, perhaps, they may bring life into the world.
However, we don’t give them as much credit as we should. Our genitals do more than we think they do. In fact, they help inform us of what it means to be human.
If you haven’t read Sex at Dawn by Christopher Ryan and Cacilda Jethá, then you and your partner have some reading to do over reading week. In this book, the authors deconstruct human sexuality from an anthropological perspective and one of the ways they do this is by looking at our anatomy. “Everybody has a story,” they write, “so does every body, and the story told by the human body is rated XXX.”
Part of the book is comparing our anatomy with those of other primates, which Ryan and Jethá believe is indicative of us being non-monogamous by nature. For example, the average penis length of a human is 5.1 inches with testicles averaging about the size of a walnut, but a four hundred-pound gorilla has “just over an inch long [penis], at full mast, and his testicles are the size of kidney beans”. The authors believe that this suggests that we are polygynous when compared to other primates. For example, some male primates have a large body to genital ratio (like gorillas) because they live in haram based societies and therefore, their sperm doesn’t have to compete with other sperm. Primates with a small body to genital ratio (such as bonobos) typically operate in societies closer to a hippy commune than a haram.
Speaking of multiple sperm donors, you’d be surprised how chemically different each ‘spurt’ of ejaculation is from one another: “Researchers who somehow managed to capture ‘split ejaculations’ for analysis found that the first spurts contain chemicals that protect against various kinds of chemical attack. What sort of chemical attack? Aside from leucocytes and antigens present in a woman’s reproductive tract (more on that later), they protect the sperm from the chemicals in latter spurts of other men’s ejaculate. These final spurts contain a spermicidal substance that slows the advance of any latecomers.”
Furthermore, the authors argue that the very design of the penis is no accident, pointing to multiple male partners at once: “The unusual flared glans of the human penis forming the coronal ridge, combined with the repeated thrusting action characteristic of human intercourse — ranging anywhere from ten to five hundred thrusts per romantic interlude— creates a vacuum in the female’s reproductive tract. This vacuum pulls any previously deposited semen away from the ovum, thus aiding the sperm about to be sent into action. But wouldn’t this vacuum action also draw away a man’s own sperm? No, because upon ejaculation the head of the penis shrinks in size before any loss of tumescence (stiffness) in the shaft, thus neutralizing the suction that might have pulled his own boys back. Very clever.”
Aren’t our bodies amazing? One might be thinking that this book is a romantic ode to the penis, but that’s not entirely true. Female genitalia is just as full of anthropological wonders as their male counterparts.
It turns out that female genitalia is better at picking and choosing sperm than we think: “Sperm competition is best understood not as a sprint to the egg, but a race over hurdles. Aside from the anti-sperm leucocytes mentioned previously, anatomical and physiological obstacles are in the vagina, cervix and on the surface of the ovum itself. The complexity of the human cervix suggests it evolved to filter the sperm of various males.” The authors state that “the cervix acts both as a filtering mechanism and as a temporary reservoir for spermatozoa during the migration towards the uterus.” It becomes clear that the female is, whether consciously or not, selecting specific sperm during and after sex. So rather than paternity being a competition between males, it is a competition between sperm in which the female decides the victor.
This book is full of information that will change the way you look at sex and your own junk. If you want to learn more about the intimate parts of you and your partner as well as the origins of our species, this is the book for you.
Genitals are an important part of what it means to be human. Without them, life wouldn’t be nearly as fun and we simply would not be here. In others words, genitals deserve more credit than they