Eve: How the Female Body Drove 200 Million Years of Human Evolution

Eve: How the Female Body Drove 200 Million Years of Human Evolution by Cat Bohannon

In Eve: How the Female Body Drove 200 Million Years of Human Evolution, Cat Bohannon sets herself an ambitious task as evidenced by the sub-title — How the Female Body Drove 200 Million Years of Human Evolution — and I’m happy to report she’s more than up to the job, turning out out a work that impresses across the board: in information and organization, in scholarship and research, in voice and wit, in breadth and depth. As such, I’m guessing it will be on my top ten of non-fiction works for 2023.

In explaining the evolution of the female body (and since one can’t separate the two, the evolution of human culture), Bohannon moves generally chronologically via sections organized by a particular body part or trait, such as milk/breastfeeding, the womb, legs, tool use, the brain, and love. The first section starts roughly 200 million years ago, and each successive segment jumps to the time scientists believe that trait first appeared in our evolutionary calendar, Bohannon offering up at the start of each chapter what she calls an “Eve”, a hypothesized (or more speculative) representative species who may first have exhibited that trait. Since each section also brings us up to modern humans, Bohannon moves back and forth in time, but the reader is always solidly, clearly grounded in “when” they are at any given moment.

As noted, the book is heavily researched, filled with supporting details via a host of studies nicely balanced out with Bohannon’s own experiences, which pepper the work in just the right amount. One of my tests for how much I enjoyed a non-fiction work is how many notes I took or passages I highlighted and believe me, there are a slew of them in this text. I’ve read a lot of popular science works that overlap with areas Bohannon discusses here: biology, paleobiology, social and political history, anthropology and paleoanthropology, archaeology, as well some titles that connect more specifically, such as Rachel E. Gross’ Vagina Obscura: An Anatomical Voyage. And even with that prior knowledge, Bohannon threw one previously unknown and utterly fascinating fact after another at me. That mother’s milk (specifically the colostrum part) acts as a “reliable laxative.” That a baby spit gets sucked back into a woman’s nipple (backwash) and that the components of breastmilk will change based on an analysis of that spit. That orcas are the only other species that have menopause. Just how bad humans are at reproducing ourselves compared to other animals (really, really bad; it’s amazing we’re still around).

Even when I knew some of what Bohannon was talking about, she offers up more details, more context, more explanation. For instance, I knew women were more likely be tetrachromats — people who can see the world in four color dimensions rather than three. But I didn’t know that while they can potentially see millions more colors, more subtle shadings, than most humans, they almost never do because “the brain determines the need, and the eye adapts according . . . If you need to see a certain color . . . you’ll probably see it … But if there’s no need? Then you probably won’t.”

And just to break things up, I also learned somewhat less useful but generally entertaining facts such as Bohannon once carried a jug around to save her pee in, that the apes in 2001 were British mimes, that she was asked at a job interview at a call center if she wouldn’t rather be “one of the girls” (unbeknownst to her when she applied it was for an escort service), and that her boyfriend at the time who told her he’d break with her if she said yes didn’t ever offer to help with rent or to have her move into his own apartment, which he had filled with 12 guitars and a poster of Tori Amos.

Those latter details give you a sense of how Bohannon keeps things playful, uses her wit and own personal experiences to give the reader a break from the book’s informational density (and it is dense — 600 pages, roughly a third of that in the form of notes). She’s also quite careful, as she conveys all that information, to make it clear to the reader just how confident the reader can be in her claims/explanations, pointing out when something is a consensus belief or is contested within the discipline, whether a study is strongly supported thanks to a significant population or a winnowing of variables or if some studies might be questioned thanks to their small sample size or the difficulty of teasing out those variables. Some of this happens in the text proper, some of it in the footnotes, and some of it in the endnotes, but it almost always happens.

Which is good, since as the book progresses and Bohannon moves farther afield from anatomy into behavior and culture, the text by nature becomes more speculative (it also becomes even more fascinating). But even when I wasn’t fully on board with Bohannon’s points, I never felt she was trying to slide something past me.

As for why read this book rather than one of the many others on humanity’s evolutionary history? Well, one reason is this acts as a much-need correction. One has to live in an impermeable bubble to not know how much women have been erased throughout history from history. And not just history. They’ve also been literally erased from science and medicine, first being simply deprioritized (out of mind out of study) and then being purposely ignored with their too-complicated bodies filled with all those pesky hormones and following those annoying fertility cycles all of which threatens to make life too difficult for scientists and doctors performing studies and clinical trials. Far easier to just assume they’re “just like” the “easier” bodies of men.

Cat Bohannon

Which is how we end up, as Bohannon informs us early on, with nearly 80% of animal studies in one representative journal from 1996-2006 using only male subjects. Or why, even in 2000, six years after NIH tried to update regulations to force studies to use more women subjects, 20 percent of studies still had none and of the ones that did, 80% didn’t look for sex differences in the results. Which explains why we only found out relatively recently that women require stronger painkiller doses to achieve the same relief of men using lower doses, which not only has consequences for pain relief itself but also for opioid addiction. Or that women under general anesthesia wake up faster than men, “regardless of their age, weight, or the dosage.”

We see another type of mental erasure in our “just-so” stories, our scientific theories explaining evolutionary events: cave art, hunting, tool use, the rise of language, etc. Why do we have tools? To hunt of course. Why are their pictures of animals on cave walls? To depict hunting, of course. Why did we learn language? To communicate so we could hunt. Notice a pattern here? And of course, when we say “hunting,” we mean men doing it (though that comes with far less certainty than is usually presented).

What Bohannon so convincingly does here, and so necessarily, is to put women back into the picture. And not by forcing them into the frame either. She’s not Photoshopping them in. She methodically, carefully, fully explains why it makes sense to place women at the center of language development. Why gynecology should be elevated to one of the top technologies that allowed humans to exist and then to thrive (and when is the last time, in the list of tools like controlled fire and language etc. you saw that word thrown into the mix?) As I said above, even when she is speculating, even when I might not wholly agree with her speculation, she is nothing but thorough and honest in her claims.

Eve is a perfect example of high-level non-fiction, high-level popular science, done right. Thorough, deeply researched, strongly supported, clearly organized, utterly fascinating, cohesive, playful at the right times in the right amount, scholarly to the right degree, accessible but not condescending or overly simplified, curated with an academic eye and conveyed in a personally engaging fashion. I loved all 600 pages, including the notes, which I read in their entirety (and highlighted large portions of). Highly and enthusiastically recommended.