Living World / Sex & Reproduction

About a decade ago, at the request of Psychology Today magazine, I had an amusing debate with Richard Dawkins about testicles. Dawkins had famously proposed the metaphor of the "selfish gene" to explain how traits in organisms can be understood from the imagined point of view of a gene wishing to propagate itself. The underlying logic of the metaphor is compelling, yet it doesn't always seem to work gracefully—as in the case of human male genitalia.

The site of human testicles seems a bizarre anomaly from an evolutionary point of view, like positioning the driver of an armored vehicle in a sack strapped to the bumper. If the whole point of the human organism is to pass on genes, why put the repository of those precious genes out front, in harm's way? Why not protect them the way the brain and the heart are protected, with thick bone vaults and, in the brain's case, an elaborate barrier to bloodborne infection?

One popular explanation is that balls need to be cool for the sperm to stay healthy. This is true, but as an evolutionary explanation, it's nutty. Evolution holds all the cards. She could easily have shaped humans so they would have a reproductive chemistry tolerant of normal body temperature. Another idea that has been dangled is that men subtly show off to women how tough we are by being willing to take such big chances with our seed. This idea can be supported by dry mathematical modeling, but really, wouldn't loincloths have undone human reproduction by now if it were true?

These old ideas about balls were bouncing around in my head a week ago when I witnessed a moment in human gene propagation of such high drama and evolutionary dysfunction that it made testicles seem quite unimportant: My wife gave birth to our first child.

I watched as the most exquisite, transcendent moment of human experience was channeled via soggy, bloody, out-of-control bodily functions. Our amazing little girl, already filled with curiosity and engaged in fearless exploration, had to squeeze through a pelvis ill-designed to admit her big brain. My wife's body was painfully torn, though no more than is considered normal. Everyone was exhausted, and were it not for the extended womb of medicine, our baby, like any healthy human baby, would have been so vulnerable as to face poor odds for survival.

Is this any way to run a species? In the precious moments between diaper changes, I've been talking with an old friend, paleontologist Niles Eldredge, about the apparently flawed design of the human organism.

One thing that strikes me is how so many people prefer to think of themselves as having a perfected body form. It doesn't seem so perfect to Niles and me. Take this whole business of walking around upright. I love the way walking rhythms turn into music, and it is a tremendous convenience to have one's hands free, but our erect body plan is unfinished and full of bad structural compromises. Hazardous birth (as a result of that inappropriately narrow pelvis) is only the most appalling; we also suffer from sciatica, knee and foot failures, and on and on.

My wife had it easy compared with the women in adjacent birthing rooms who decided to forgo the epidural. They chose epochal pain for personal reasons. Various people, including members of the hospital's staff, encouraged us, too, to try "natural" childbirth, as though failing to confront another human design flaw were somehow more true to our evolutionary roots. While I respect the choices women make at this most personal moment, I don't think such a thing as natural childbirth has ever existed for the human species.

An image came into my mind as I watched the terrifying, wonderful process of human birth. Imagine a leaping athlete, perhaps a grown-up version of our energetic baby girl, her motion frozen in place by the flash of a camera. The photograph documents all the quirks of a single moment's posture, one the athlete could never sustain. This is the nature of the human species. Ancient technologists—known today as midwives, herbalists, warriors, fire makers, and shamans—long ago learned to protect vulnerable newborns and damaged mothers. That well-intentioned interference had an unforeseen effect: It helped freeze the human body in its current form by easing the selection pressures that are evolution's scalpel.

Niles and I have mused about how evolution might have refined the hominid design if we had given her a chance. A different species might have emerged, one that would remember the likes of us as merely a transitional phase. How might this hypothetical species, which I'll call Eureka sapiens, have turned out?