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

“That’s the real problem with origin stories like the one in Genesis: our bodies aren’t one thing. There’s no one mother of us all. Each system in our body is effectively a different age, not only because the cellular turnover rate differs between cell type and location (your skin cells are far younger than most of your brain cells, for instance), but also because the things we think of as distinct to our species evolved at different times and in different places. We don’t have one mother; we have many.”

Bohannon challenges the myth of Eve in the Book of Genesis, believing it to be overly simplistic and treating female individuals, and humanity, as coming from a singular source. However, she believes that many figures have contributed to the creation of female bodies and humanity. She soon details the various pre-human Eves that contributed to human evolution, as well as the Eve of humanity that continues humanity’s evolution today. She also regards these myths as unrealistic in comparison to how species come to be in life. Because humans evolved, it is important, according to Bohannon, to see how female ancestors developed different aspects of the female body. The introduction of Eves also establishes The Evolution and Historical Impact of the Female Body.

“But colostrum is especially dense with immunoglobins: antibodies tagged to respond to pathogens that the mother’s body knows to be dangerous. In fact, before we discovered penicillin, cow colostrum was commonly used as an antibiotic.”

Bohannon explains that colostrum and its evolutionary predecessors secreted by Morgie and the other Eves is highly nutritious for babies and gives their immune systems a jump start. This challenges the beliefs in the Middle Ages that colostrum was rotten and less healthy, many of which were believed by female individuals and also pushed by male individuals like Bartholomaus Metlinger, a man who did not lactate. Bohannon is Debunking Myths About Female Biology by explaining that colostrum is good for babies and that misinformation about female bodies does needless harm to both mothers and babies.

“And so, Morgie’s legacy was both boon and bane for the rise of Homo sapiens. Ancient cities had major overpopulation problems, and these problems bled into their origin stories. It seems, for instance, that the tale of Noah and the ark wasn’t originally about sinful humans; it was about urban overpopulation and birth control.”

Bohannon hypothesizes in this passage that Morgie’s development of milk and introduction of wet nurses led to human urbanization later. However, this caused overpopulation, which had devastating effects on cities, including wider spread of infectious diseases. The Sumerian flood myth that predates the Noah’s ark flood myth blames the necessity of the flood on overpopulation and resolves the conflict by having the gods introduce mortality, sex work, wet nurses, and birth control. Bohannon finds this to be a far more realistic and reasonable flood myth because of this acknowledgement of overpopulation’s harm and the benefits of birth control.

“What’s not normal is letting eggs incubate and hatch inside your body, where they can do all kinds of catastrophic damage. What’s not normal is building a placenta and anchoring a developing fetus to the wall of the uterus, thereby transforming the mother’s body into a kind of H. R. Giger fever dream meat factory. What’s not normal, in other words, is giving birth to live young.”

Bohannon explains the evolutionary abnormality and novelty of the placenta and uterus at the time of Donna’s existence. She uses humorous language to emphasize the significance of this change and how it changed mammalian species permanently. This establishes The Evolution and Historical Impact of the Female Body by showing that the development of the womb is, when thought about from evolutionary and scientific perspectives, quite odd compared to how other animal species had been adapting previously.

1.  “So, Donna, the Eve of the modern eutherian uterus, had her toe pads in the right spots. She had a fondness for the sweet crunch of live insects, which she’d catch with the cone-shaped, jagged teeth that lined her delicate, narrow maw. Her ears, set close to the hinge of her jaw, were furred, as were the rest of her. Unlike Morgie, her legs didn’t splay to the side like a lizard’s, but instead ran more vertically from pelvis to ground.

For eutherians, the alteration in the pelvis is pretty crucial. In order to fit a swollen uterus, you need a pelvis that is more of a bowl shape. Rather than scrambling along with our bellies dragging on the ground like alligators, we evolved in such a way that our torsos naturally lifted higher so that the upgraded pelvis could support a pregnant placental uterus.”

The passage shows how Morgie’s newly placental descendants changed their bodies to accommodate their uteri. The contrast between the formats of Donna’s and Morgie’s legs and pelvises shows that going from a monotreme to a placental species was a major evolutionary change. The passage also shows The Evolution and Historical Impact of the Female Body by establishing and hinting that this change would only be one of many and that female pre-humans’ bodies would continue to change and mold greatly to better accommodate uteri and growing embryos and fetuses.

“Straight women’s ears may be better tuned for a world of needy primate babies because they calibrate their instrumentals more regularly than men, and women in general—whether straight or not—simply have more sensitive instruments for hearing than males, with those abilities better preserved over time. But if we think of Purgi’s tree-borne face as a sensory array—one ready-made for both sensing and communicating with her babies—then maybe we should rewind the tape. Hearing isn’t the only thing we do with our children. Though the first sound of a baby’s cry helpfully confirms that the child is alive, mammals do something far more ancient with children when they’re born: We smell them. We put our faces close to our pups, whatever species they may be, and we breathe them in.”

This passage shows that the development of stronger human senses stemmed from the female ancestors’ necessity to hear and smell their children. Female individuals have stronger senses than male individuals because they need them to care for their babies and because their ancestors required strong senses to survive and detect good food. The quote also incorporates The Intersection of Science and Gender by comparing and contrasting female and male senses, showing and confirming that female individuals relied on these senses even more than male individuals did throughout human history.

“The theory for why we lost it is that Purgi and other primates slowly evolved to become more visual and less scent-driven. Maybe that’s because, for primates at least, life in the canopy made it harder for them to distribute social stink than creatures on the ground. Whatever the reason, the further along primate evolution you go, the flatter the face. The eyes move forward. The nose shrinks. Maybe you even turn off a bunch of your olfactory genes, as is the case in the human genome. Eventually, you start knowing the world by seeing it, rather than smelling it.”

Bohannon explains that humanity’s loss of the ability to smell things more strongly like their ancestors came from the adaptation of Purgi and her descendants into primarily visual animals. As a tree animal, she needed reliable sight that would help her find safe food and avoid predators. In the modern world, female humans have significantly stronger sight and the ability to see far more visual details and colors than male humans. This shows that stronger sight is a female-derived trait from Purgi and, therefore, thematically supports The Evolution and Historical Impact of the Female Body.

1.  “If you have two X chromosomes, as most women do, it’s incredibly unlikely that you’ll end up being red-green color-blind, whereas roughly 10 percent of men are. If red-green color vision was obviously selected for in diurnal primates, why was it located on the X chromosome?

It’s possible this type of color vision was more advantageous for the primate Eve than for her consorts and sons. Perhaps being more efficient at spotting more nutritive foodstuffs (extra-sweet berries, extra-tender young leaves) made a real difference in pregnancy and breast-feeding. If Purgi utilized the same sex-specific parenting strategies as many living primates do, foraging for herself and her infant offspring, then the survival of the young depended far more on the female than the male. In other words, there was more pressure to see red and green on the newly diurnal Purgi than there was on her male counterparts.”

This passage explains why colorblindness is an X-linked trait and why male individuals are far more likely to be red-green colorblind. Historically, male humans and male hominins did not need to know the difference between distinct colors because it was mostly female humans and female hominins that foraged for food and needed to distinguish between different shades to know which foods were safe to eat. In addition, it was Purgi and other females of her kind that foraged for food during the day, and their new diurnal schedule allowed them to better detect the color differences.

“Scientists found Ardi’s skeleton near Aramis, Ethiopia, in the mid-1990s, but it took the better part of a decade to analyze the fossils and realize what they’d found: the earliest bipedal ape, the Eve of women’s legs, hips, spine, and shoulders. Ardi is the best evidence we have for the root of the sex differences in men’s and women’s musculoskeletal system. She is the reason there are men’s and women’s divisions of competitive sports. She is the reason women have crappy lower backs and knees. And she is also the reason women are more likely to survive a zombie apocalypse (should you be concerned about such things).”

The passage explains that Ardi’s musculoskeletal system caused her descendants, including female humans, to suffer from many of the same problems she had. The flaws in her bipedal evolution have had both positive and negative consequences for female bodies, and they are all significant. Bohannon uses humor to lighten this unfortunate fact, such as with her zombie apocalypse joke. She later explains, though, that Ardi’s endurance was what made her and the switch to bipedalism successful.

“But the most compelling arguments for why hominins evolved to walk upright aren’t about short-term performance. They’re about endurance. It’s a question of range.”

In this quote, Bohannon explains that while male bodies are physically stronger than female bodies in most cases, female individuals have as much, if not more, endurance. It is this endurance that made Ardi successful in introducing bipedalism to the hominins and what helps female individuals achieve their goals now. Bohannon stresses that in many ways, endurance in difficult times is even more important than physical strength or speed, and female individuals are highly durable.

“But the dawn of midwives wasn’t the only thing in play for our Eves. There was another, wider foundation they were able to build on. Human ‘gynecology,’ at each stage of its evolution, also includes many types of birth control, abortion, and other fertility interventions. Female reproductive choice is ancient.”

This quote drives The Evolution and Historical Impact of the Female Body by establishing gynecology as the most important innovation of Habilis. A species using adaptation and tools to make changes to reproduction is groundbreaking in animal science and shows the extraordinary nature of hominins. Habilis’s skills with gynecology would later help define methods of gynecology in both early and modern humans and allow them to better control their reproductive destinies.

“So maybe we need a better narrative to describe humanity’s ‘triumph.’ Our story doesn’t begin with a weapon. It doesn’t begin with a man. The symbols of our ultimate technological achievements shouldn’t be the atom bomb, the internet, the Hoover Dam. Instead, they should be the Pill, the speculum, the diaphragm.”

Bohannon suggests that scientists and others change the narrative of human evolution. She argues that humanity does not begin with male hominins using violence but with female hominins gaining control over their reproductive health and creating tools to help them reproduce when they are ready. Following this quote, Bohannon reimagines the montage in Kubrick’s 2001: A Space Odyssey from a female evolutionary perspective.

“Fair warning: if we’re going to ask questions like these, we have to take every one of those famously sexist ideas seriously. After all, if the proposition is that the seat of the Self is sexed—not just gendered, but sexed—then there should be some scientific data to support it.”

Bohannon addresses the sexist stereotypes about female brains to scrutinize them from an objective, scientific perspective. She intends to use this as a way of Debunking Myths About Female Biology that are harmful and inaccurate. At the same time, she wants the audience to understand where these stereotypes come from and how misinformation and confusion about statistics can impact science about gender, showing The Intersection of Science and Gender.

“But because speech in many such places is controlled by formal constraints, like being called on by a teacher, the likelihood of your being called on is the biggest predictor of how many words you’ll speak. As a rule, women and girls are called on less in business meetings and classroom settings, and as a result they speak less than men.”

Bohannon denies the legitimacy of the stereotype that female individuals talk more than male individuals by showing that they truly speak less. Instead, female individuals, even when they are talking less or an equal amount, are perceived as talking more. This supports Debunking Myths About Female Biology by challenging this stereotype and showing that it is largely caused by higher female linguistic skills on average and by sexist bias.

“There’s a moment in every young girl’s life when she realizes that she’s being watched. That her body is a thing that’s seen, and that men are the ones who are doing the seeing.”

This quote presents the frustrating reality of being female in a sexist society. Bohannon presents a phenomenon that many female individuals are familiar with: the experience of being seen as an object. This level of misogyny often pushes female individuals to suppress who they are, not allowing them to show their full intellect, individuality, and power because it challenges patriarchal authority.

“Human brains are long evolved to carefully track how each individual fits into a larger group. We each have specialized roles in our groups—roles that can shift, depending on circumstance. We spend years carefully learning how to successfully live inside our deeply social world. It’s one of the most characteristic features of our species: that extended period of social learning. Our brains are built for it. Our species depends on it.”

Bohannon uses this quote to show how humans’ heavily social brains absorb social codes and internalize them. This creates a need to choose whether to adapt to social settings and survive or deviate and possibly be criticized, rebuked, shunned, or even punished. This creates tension and pressure in humans to cooperate with and follow those around them, even if it does not feel right for them and they do not want to.

“It really is like a magic trick. Without moving anything, without building anything, with little more than a skittering of electricity along tiny threads spindling off the ends of cells, your brain tells your throat and mouth to make a sound. With just a few pulses of air, the sound jumps across space to someone else’s ears, and in hardly any time at all—milliseconds—your idea arrives in that person’s brain.”

Bohannon expresses amazement at how rare it is for species to use language to verbally communicate and that humans are the only animals able to do it. The growth of humans’ brains has allowed them to reach one of the greatest evolutionary accomplishments yet through this adoption of speech. She describes the act of it in detail to show not only the evolutionary greatness of it but also how humans take this action for granted.

“Human mothers have evolved to be language engines—prodigious users and teachers of language. This is especially true during the synaptic blooming of their children’s brains. All the while, how mothers talk to their babies is so ingrained, and so clearly universal, that scientists have even come up with a name for it.”

The quote shows how the spread of human language has been largely reinforced by the communication between human mothers and their babies. This communication has not only taught babies language but also helped them grow cognitively and emotionally. Furthermore, the quote introduces the key term “Motherese,” which refers to this manner of talking.

“Rather than thinking of menopause as a thing we evolved to provide extra child care, we should think about what it really means to be old enough to remember events that neither your children nor your grandchildren have experienced.”

The quote uses The Evolution and Historical Impact of the Female Body to show that menopause has played an important role throughout Homo sapiens’ history. Longer female lifespans allow them to be elderly mentors for their communities far longer than their male counterparts, and female individuals often provide useful wisdom in helping their communities. The presence of wise women in many human cultures throughout history shows this.

“That’s the real story about menopause. It’s not the night sweats. It’s not the dry vagina. It’s not really about menopause at all. It’s that we outlive the men we love. We outlive our brothers and husbands and lovers and friends. We have to live on, all of us, and watch them go.”

Bohannon describes menopause in female human biology as a story of both life and death. Death begins to take the people around menopausal people, especially the male humans that they love. Life continues for them, allowing them to still find meaning and happiness within the pain and loneliness. However, this long life requires them to move through the painful losses of those they love and to contemplate their lives as they come closer to the end of life.

“I am not the Eve of human love. That isn’t why I told you this story. There probably isn’t an Eve of love, really. But I am an Eve, as are you, just like every single living human today. We are the drivers of our species’ tomorrows. We are all writing the future of humanity through the choices we make, day to day, in these bodies we inhabit, in the children we have or help raise and protect, in the societies we push against and collaborate with and innovate on. We live, at all times, both in the present and in the long rivers of evolutionary time. So these lives we’re living are all the lives of an Eve.”

While Bohannon has spoken about the Eves of the past throughout the book, she now addresses the Eves of the present and future. She asserts that every female individual is an Eve, with multiple possibilities for human innovation, growth, and evolution as they live their lives. She uses the key term “Eves” multiple times in the quote to show the importance of Eves as innovators and creators.

“Ever called a woman a home wrecker? Or even thought it? Ever been mad at a woman—maybe even a woman you’ve never met—because you heard she had an affair with a married man? Ever found yourself angrier at the woman than the man, even though he was the one who was married and ‘ruining’ his marriage?

Yep. Me too.”

Bohannon uses this brief questionnaire to show her readers that they are not immune to sexist ideas and that even she has been guilty of them. She also uses this to highlight that internalized misogyny is a serious problem for female individuals and that it shows how female individuals could choose to side with patriarchal structures in exchange for safety and security. To combat sexism, people must, in part, combat sexist double standards and let them go.

“We’re escaping our evolutionary destiny, in other words. And we’re doing it by being human: being smart, collaborative problem solvers who tell each other stories and revise those stories to make better ones.

But such progress (for lack of a better word) is always fragile, and right now two fundamental things are standing in the way: asteroids and assholes.”

Bohannon asserts that overcoming sexism and the horrible atrocities and injustices it brings is possible. Humans have been able to change the world with their ability to adapt and make plans in the past, and they can make changes for the better if they try. However, she warns that people must take the threat of climate change seriously; otherwise, there will be no world or human race to save, and unjust and destructive institutions will take advantage of the world’s devastation to gain control. She then warns that they must stand against those who wish to gain power at others’ expense and subjugate those they hate.