It can taste, smell and sing. It can be a corkscrew, a crowbar or a hypodermic needle. It can stretch up to nine times your body length (if you’re a barnacle); be a detachable tentacle covered in suckers (if you’re an argonaut octopus); or even see, using light-sensing cells that guide it smoothly to its destination (if you’re a Japanese yellow swallowtail butterfly). Or, it can be a limp, fleshy tube, hardly worth writing home about, if you’re a human.
It is the penis, as you’ll know if you’ve read Phallacy: Life Lessons from the Animal Penis, biologist and journalist Emily Willingham’s recent exploration of phallic diversity across the animal kingdom.
Meanwhile, another book argues that what we need is even more penis science. GUYnecology: The Missing Science of Men's Reproductive Health, by Yale sociologist Rene Almeling, asks why medicine has failed to fully probe “the male gonad,” as one scientist put it, and its role in human reproduction. Almeling explains why no medical specialty exists that is devoted to male reproductive health—the guy equivalent of gynecology. When it comes to penis science, it seems, men have gotten shafted.
At first glance, these two very different books appear to point to the same enduring truth: that scientists—and readers—remain as penis-obsessed as ever. Or, as Willingham puts it, “Nothing gets clicks like a story about dicks.”
Actually, it’s the opposite. In both, the flashy focus on the male member serves as a Trojan horse (pun intended) for a very different message: that a culture of phallus-worship has slanted the science in crucial and sometimes unexpected ways. On the one hand, we’ve inflated the role of the penis in genital evolution; on the other, we’ve left the male contribution to infertility, genetic abnormalities and other reproductive consequences unexamined. The result is stunted, lopsided science that shows only one side of the story.
Consider that myriad beetle species are classified solely by their penis shape, while the true breadth of vaginal diversity has yet to be explored. This tradition has deep roots: Going back to Charles Darwin, who waxed poetic on the wonders of barnacle dongs, biologists have trained their lens on the penis while remaining largely uninterested in what vaginas were doing. Yet penises don’t evolve in a vacuum. All those traits we ooh and aah over—length, girth, bristles—are shaped by vaginal evolution, and the mutual dance between the two that plays out over generations.
Today, as more women and LGBTQ scientists enter the field, we’re finding that vaginas, far from passive tubes for ejaculate, are active organs that sort, store and reject sperm. Kangaroos have three vaginas (two for sperm reception, one for joey ejection); swallowtail butterflies see out of theirs; and duck vaginas spiral and curve in a penis-repelling labyrinth. Even for non-vagina-lovers, these facts help us understand how genitals evolve as a whole. Both are part of the same unified story—a much richer tapestry than just one body part can tell. Leaving one out, whichever one, blinds us to the fuller picture of sex and sexuality.
Similarly, leaving guys out of gynecology paints a false picture that, beyond sperm, men don’t contribute much to human reproduction. While medical messaging hits women over the head with the fact of their ticking biological clocks, men are rarely told how their health and age will affect their offspring. This incongruity gives the impression “that reproduction is women’s business—that it occurs primarily in women’s bodies and is solely women’s responsibility,” Almeling writes. In reality, sperm age and quality likely play just as large a role in rates of developmental disorders and infant survival as eggs do—to say nothing of the interactions between the two.
Both examples reflect a deeper flaw in science’s approach to sex: the assumption that sex can only be either/or, two trains that run along separate, parallel tracks. Again and again, biology has proved this not to be the case—chromosomally, hormonally or genetically. For instance, we usually consider the presence of a penis to indicate a male, yet the hyena famously gives birth through her clitoris, which is so large that she can use it to mount the male. The female seahorse wields a long tube that looks an awful lot like a penis, which she uses to deposit eggs in the male’s pouch. So much for the penis as “the throbbing center of masculinity,” as Willingham puts it.
All of which leads us to the question: what is a penis? “It’s kind of boring, honestly,” Willingham said on a recent episode of the podcast Taboo Science. Basically, we’re talking about a fleshy organ lined with columns of spongy tissue, which can fill with blood and grow rigid. As it turns out, that’s also the definition of a clitoris, which develops out of the same embryonic structures and is made up of the same tissues. Think of it as a taco or a burrito: same ingredients, different configuration. Sure, one might have a urethra and sperm ducts running through it, but in the end, they’re far more alike than different.
Yet thanks to the assumption that anything large and powerful must be male, a phallus with more imposing qualities—like the hyena’s—gets dubbed a “pseudopenis,” "masculinized" or “malelike.” Those who spend a lot of time with human genitalia see it differently. “What I’ve come to realize is that everything a man has a woman has; everything a woman has, a man has, anatomically,” says Dr. Marci Bowers, a gender affirmation surgeon in Palo Alto who has done more than 2,000 male-to-female surgeries. “The penis is just a large clitoris. In fact, I don’t know why they don’t just call it a large clitoris.”
Here’s why: because human biases shape scientific knowledge, and much of what we know about our nether regions has been shaped by lazy, antiquated stereotypes about what men and women are. Looking past the penis and beyond the binary categories of male/female, penis/vagina (or, more accurately, penis/clitoris) opens our eyes to the full spectrum of gender and genitalia in all its glorious permutations. It makes for better science, and a deeper understanding of genital evolution and reproductive health.
It’s time to take the penis off its pedestal, for all our sakes.