Why Giving Birth Hurts
Y: Don, you sure are lucky don’t have togive birth. I’m glad we’re an intelligent species, but boy, that infant head feels mightylarge going through that narrow birth canal. And then, after all that, the babycomes out facing down and backwards, which means you’re helplessto assist it, or even to untangle it from the umbilical cord.
D: Well, Yeal. According to evolutionaryanthropologists, babies of the earliest humans had a fifty-fifty chance ofcoming out facing backwards. This was a result of humans learning to walk ontwo feet. As the pelvis became optimized for walking, the birth canal developedtwists and turns that meant the baby had to rotate in order to keep its headand shoulders aligned with the widest part at all times.
Y: And then our brains also got bigger.
D: Which meant more twists and turns.
Y: And backwards-facing babies, stupid,huh?
D: Well,you know,Yeal.Some of the earliesthumans learned to compensate for the difficulty of giving birth by receivingassistance during childbirth, which made a huge difference in terms ofsurvival.
Y: So there might be an evolutionaryadvantage to having someone help you give birth.
D: Some anthropologists certainly think soand conjecture that human females who gave birth to backwards-facing babies,and females who had assistance because they felt particularly anxious about thebirth, ended up doing better than females who didn’t. Afterall, if problems arise during labor, having another person around can make thedifference between life and death.