Red Blood/White Milk - How Women's Sexuality Shaped Human Evolution

Excerpted from
Sex, Time, and Power: How Women's Sexuality Shaped Human Evolution
By Leonard Shlain, M.D.

In Genesis, the Serpent, a reptile, hisses into Eve's ear how she might acquire self-awareness and escape from her reptilian brain. She, not Adam, takes the first bite of the forbidden fruit, and it is she who then teaches him what he must do to acquire the Great Gift. The heavy price Eve subsequently paid to possess this knowledge was the grave sentence God leveled against her and her daughters: "I will greatly multiple thy sorrow and thy conception; in sorrow thou shalt bring forth children" (Genesis 3:16).

The Genesis story contains all the elements that I suggest actually converged at the dawn of our species, though in a somewhat different sequence. Maternal mortality was the primary cause, not the punishment, for the emergence of the first woman's ego-consciousness. Eve did not commit the Original Sin; rather, the initiating event of our species was her exercise of Original Choice. The first man was not prodded by a threat to his existence comparable to what a female had to experience nine months after she stopped bleeding. He evolved cognitively in the area of sexual relations because she presented him with a threat that he could not ignore.

Adam confronted a knotty problem no other male of any other species ever had to contend with-a female with a mind of her own. She could refuse to mate with anyone, anywhere, anytime. Just as legend has it, that before Eve there was Lilith."

A quirk of genetic linkages called pleiotropism spurred the first man's rapid evolution. A human has twenty-three pairs of chromosomes. Only one of the twenty-three is considered the sex pair. As long as the gene controlling a trait is not on the female's X or the male's Y chromosome, the mixing of maternal and paternal chromosomes at conception guarantees that an attribute evolving in one sex, such as a nipple or a larger frontal lobe, evolves simultaneously in the opposite sex. As the female was gaining the mental grit necessary to assert her independence, she forced the male to respond to her act of will, because his individual fitness and the survival of the entire hominid line was at stake.

Eve's independence compelled Adam to hastily assemble enough mental wattage to formulate the Brobdingnagian question "What does a woman want?" Stripped down to its essence, what a man really wants to know is: "What must I do to convince her to let me have sex with her?"

Like Oedipus' encounter with the Sphinx, death awaited a man's genes if he failed to solve the riddle an aloof woman posed. Furthermore, the riddle was a multiple-choice question with protean answers, some of which might be correct in one situation but inappropriate for another. The enigma was complicated enough to force a man to evolve a big brain with large frontal lobes capable of dealing with so complex a mystery

Of course, if he could not persuade her to join him willingly, he could, as a last resort, overpower her with his superior size and strength. However, aggressive males forcing themselves on unwilling females was not a satisfactory solution to the psychosexual emergency Gyna sapiens precipitated with her first adamant No! Sheer aggression between males and females has never, ever been used as the standard sexual strategy for any other species. From an evolutionary point of view, intersex mayhem would be too costly and dangerous to maintain. Rape in the wild remains an oddity rarely observed. To install it as a mainstream adaptation in the hominid line would run counter to the tendency toward increasing cooperation that had been building steadily among the highly gregarious and social primates."

With rape relegated to a rare and hazardous option, the human male found himself at a significant disadvantage as long as the female retained veto power over sexual congress. Nevertheless, the use and threat of rape in historical cultures has introduced a bitterness between the sexes that has poisoned male-female relations.

Since it was literally a matter of life or death to her. the woman retained the upper hand. Fortuitously for the frustrated male. Natural Selection stepped in and gave him an unexpected assist. Sophocles warned, "Nothing vast enters the life of mortals without a curse." Her power to refuse sex was undeniably vast. The curse: Human females began to leak the crucial element iron at persistently alarming rates from a variety of avenues throughout their entire reproductive life

The depletion of woman's iron stores balanced her veto. Together, these two new adaptations-the ability to say No! and chronic iron loss-shaped the course of the many diverse human cultures that flowed from these two remarkable evolutionary developments. In combination, they also provide the answer to the timeless question "What do women want?" At its most fundamental level, the level present at the dawn of our species, what every woman wanted then was the substance that bestowed health and vigor on her and ensured that she birth smart babies. Ancestral women wanted iron. To understand better why iron is so critical and how it undergirds the structural I-beams of a human's pre-eminent attribute-intelligence-we must make a brief digression.

We owe our superior mental agility to our big brain. Brains run on a mixture of two fuels: oxygen and glucose. The latter can be extracted efficiently from either fats, proteins, or carbohydrates courtesy of an enzyme system employed by the liver called the Krebs cycle. Every morsel you eat can be converted to a molecule of glucose.