Human Evolution and Women's Sexuality -- Part I: Women Acquire Free Will

 By Kristy McCaffrey

Women bleed. Men don’t.

According to biologists, there are between ten million and thirty million different species of life on earth. Only four thousand are mammals. And only one—humans—experience blood loss on a regular basis. If fertilization doesn’t occur each month, a human woman will menstruate, shedding the lining of her uterus along with several tablespoons of blood every four weeks. There are mammals who exhibit a type of menses—elephants, bats, shrews and hedgehogs—but it’s insignificant to their health. And out of approximately 270 different primate species, 31 menstruate, but again, the blood loss is negligible.

Over 150,000 years ago, the hominid brain completed a rapid inflation that added one-third to its size. This wasn’t good. No other species has as difficult or as dangerous a labor as a human woman. And no other female needs as much help from others to give birth.

The human brain consumes nearly 25 percent of every heartbeat’s oxygen-rich output. The brain’s pH and temperature must be narrowly regulated. The body must constantly clear the accumulating toxins from the fluid that bathes the brain. Why do we have such a large brain that requires so much of our body’s resources? In his book Sex, Time and Power: How Women’s Sexuality Shaped Human Evolution, author Leonard Shlain posits that it has to do with three things: sex, iron, and time.

The most amazing feature of today’s human woman is that she has the willpower to refuse sex around the time of ovulation. She can even remain celibate, if she so chooses. This is a direct consequence of birthing babies with large heads, which resulted in a high maternal mortality and painful childbirth.

A major overhaul of the brain was required for females to acquire the ability to exercise free will. With the expansion of the neocortex and the frontal lobes, along with the refinement of highly-specialized areas of both hemispheres, a female gained control of her sexual urges, much more so than the male. She acquired the ability to contemplate the relationship between mating and childbirth, a dangerous endeavor for her. She gained time to reflect, to understand that nine months after copulation resulted in offspring. She was able to connect the past with the future.

Female women underwent a major transformation because they were dying in childbirth. By gaining control of her sexual urges, she was able to control conception. And this would have profound effects on both women and men through time.

Don’t miss Part II: Women Bleed And There’s No Practical Purpose

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