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

by Cat Bohannon

Some evolutionary biologists now believe that women evolved to have fatty hips precisely because they’re specialized to provide the building blocks for human babies’ big brains. Since we can’t get enough of those LC-PUFAs from our daily diet, women start storing them from childhood forward. Other primates don’t seem to have this pattern.

Most women’s bodies begin preparing for pregnancy in childhood, not because it’s a woman’s destiny to be a mother, but because human pregnancy sucks, and our bodies have evolved ways to help us survive it.

Milk with a lot of cortisol tends (at least in rats and mice and certain kinds of monkeys) to produce baby personalities that are less risk seeking, and those traits seem to persist through the individual’s lifetime.

Being social takes a lot of energy. If the milk you’re drinking—which as a baby is all you’re drinking—has fewer sugars in it, or if you’re able to nurse less often than you’d like, you have less energy to spare. You’re going to want to conserve the energy you have for growing your young body into something that can survive to adulthood.

The things that let us survive in the suck are the things that make us human. Yes, our capacity to innovate, but also our ability to endure in the worst conditions. To keep at it when we’re already tired. Our ability, in other words, to not give up.

Without a hungry person nearby, a fork is just a stick with some pointy bits—tool use, in other words, is about the relationship between the object, its intelligent user, and the world in which both are situated.

And it’s the species that are less specifically adapted to an ecological niche who are the ones most likely to make it.

What grandmothers do, in other words, is remember. Living a really long time as a social mammal is good for two things: reinforcing the social status of adult children, and ensuring the well-being of the group overall in a crisis by remembering how to survive in a world that changes over time.