Sex, Time, and Power Page 4
Besides changing the physical structure of an organism, genetic mutations can also alter an organism’s behavioral responses to new environmental challenges. Unfortunately, behaviors leave a fainter imprint on the archeological record than do skeletal remains and are therefore harder to discern. Nevertheless, we can surmise that Response W most likely prodded members of the new species to acquire novel modes of behavior. We can deduce this from the fact that the human brain’s major design modification occurred primarily in the frontal lobes—the part of the brain that controls such uniquely human behaviors as speech, long-range planning, delayed gratification, and complex puzzle solving.
The behaviors of all organisms can be divided into two basic kinds. The first are those that promote the survival of the individual in response to the dangers and opportunities presented by its surroundings, particularly those concerning feeding, fighting, and fleeing. The second kind—courting, mating, and nurturing offspring—ensures an individual’s reproductive success, or, to use the term preferred by evolutionists, its fitness. The first set of behaviors help the organism to attain successfully the age of reproduction; the second set enable the organism’s genes to be represented in the next generation. (The term “fitness” can apply to advantageous natural or sexual selection.) If an organism fails in either one of these endeavors, it forfeits its place in the evolutionary game.
There is little evidence that when Homo sapiens first made its appearance any major changes in feeding, fighting, or fleeing occurred. The cooperative killing of woolly mammoths would begin much later. But there is much to suggest that the second category, the one having to do with sex and child-rearing, underwent a profound alteration, separating Homo sapiens from all the species that had gone before it.
Although Homo sapiens displayed features and behaviors quite different from those of its precursor species, it appears that the female of the human species, but not the male, “passed through a bottleneck.” She emerged profoundly transformed, displaying some novelties that did not exist in any prior female of any other species. Some of her new features had been present in earlier species, but in the human line they underwent modifications of a significant magnitude. The male, on the other hand, modified his behavior mainly in response to the challenges posed to him by the new female of his species.
This asymmetry in the reprogramming rate between the human sexes drastically altered the way the two related to each other, setting the stage for considerable future conflict and misunderstanding. The relations between men and women would generate great outpourings of emotional anguish that have reverberated down through the seventy-five hundred generations since a few genes of African Eve rearranged the tumblers of her genetic code. The asymmetry also created the conditions for an extraordinary dimension to human love and an ongoing cooperation between members of the opposite sexes unparalleled in its degree and duration in any other species.
Contemporary men and women are living relics of bygone days. In the short span of years that we have existed as a distinct species, insufficient time has elapsed to depart radically from the physiological and behavioral patterns we employed to respond to the conditions we found ourselves in at the dawn of our species. Evolutionist John Bowlby called this the “Environment of Early Adaptiveness.”2 He proposed that the environmental challenges existing during the Pleistocene age molded us into the species we are today.*
Since our genetic makeup has changed very little in the last 150,000 years, I will make the key assumption that the main features of modern men’s and women’s reproductive life histories do not differ substantially from those present at the outset of our species. There can be no doubt that culture can affect sexual behaviors, but the features that I will be referring to are more basic. For example, I assume that the average length of a contemporary woman’s menstrual cycle and that of a current man’s obsession with sex are both innate traits that ancestral humans exhibited. (To engage in these speculations, I will make a series of generalizations about men and women. Describing only the crest of the bell-shaped distribution curve of both male and female human behavior, I will not list the many, many exceptions that exist. As a place to begin, let us suspend judgment temporarily and assume these premises are reasonable.)
I will hypothesize that the male’s behavior evolved soon afterward in response to the female’s lead. In fact, I will argue that the history of our species could be written from the perspective that males have spent the last 150,000 years trying to regain the power they so emphatically lost to females when we differentiated away from Homo erectus. By examining the habits of modern human males and females, we can infer the many changes that emerged when the new, improved Homo sapiens female debuted in Nature’s garden. I will briefly describe these features now, but I will revisit each one in more detail in the coming chapters.
The catalogue begins with the absence in Eve’s daughters of some sort of signal that would inform a male that they were ovulating. Unlike the vast majority of other females, the one belonging to the human line does not advertise her ovulatory burst. With very few exceptions, other species’ females have a distinct period of sexual receptivity, during which they experience a powerful instinctual drive to mate. To the males of her species, a female emanates a distinctive “green light,” whether olfactory, visual, auditory, gestural, or some combination thereof. These episodic heights of female sexual desire are exquisitely timed to coincide with her ovulation. Previously uninterested males are alerted by her attention-grabbing signals.
Estrus, as this upsurge is called in female primates, promotes harmony between the sexes. When both male and female are equally excited about mating, it is likely that they will have an amicable and mutually rewarding encounter. Obviously, a considerable benefit accrues to the species if mating occurs in synchrony with ovulation. Sperm meets ovum, and conception occurs. Eve’s daughters, however, lack this most basic sexual semaphore, having replaced it with concealed ovulation. Human ovulation is so cryptic that most women remain unaware when, precisely, their eggs have departed from their ovaries.
Further obscuring the timing of her ovulation, the human female acquired the potential to engage in sex, if she desired, 365 days of the year, during pregnancy, lactation, menstruation, and even after menopause.* An alternative way to state this unusual condition would be to say that the human female does not experience a distinct period of estrus because she is in a state of constant estrus. Precious few other species’ females could hold a candle to the human female in this department. No other species has so definitively uncoupled sex and reproduction as the human line. Since sex is so intricately intertwined with reproduction in the other three million sexually active species, what would have been the reason that Natural Selection abandoned this successful strategy in humans?
Another innovation: Some human females experienced a prolonged orgasm capable of multiple sustained repeats. Orgasms, both male and female, are intensely subjective, and we cannot measure with confidence the degree of other female species’ orgasms. And yet no nonhuman female, in her observable behavior, comes anywhere near to attaining the heights of sexual pleasure manifested by a woman in the throes of her orgasm.
The male’s orgasm, in human and other species, is a necessary component of his ejaculation. It is followed by his rapid withdrawal and prompt disengagement. Only in the human can the female notify the male through vocal or body language, after the completion of his delivery call, that she is not finished, and that she expects him to continue until further notice.
Moreover, the variety of sexual positions used in human intercourse exceeds that of virtually all other species. Women became the first land females to habitually copulate face to face with their partners, and they became the first females to increasingly take advantage of an alternative position: mounting a supine male.†
Another feature of human sexuality is the prolonged period of sexual foreplay that occurs prior to penetration. Many other species engage in elaborate mating and court
ing rituals. However, when they finally get down to business, sexual foreplay is virtually nonexistent. The human male, in contrast, seems to have grasped the key fact somewhere along the line that it was in his best interests to expend considerable time and effort preparing his partner so that she, too, could experience pleasure. Concern for the pleasure of the female he is preparing to penetrate is not a motive that one would impute to the amatory repertoires of any other species’ males.*
Biologists estimate that there are between ten million and thirty million different species of life-forms on earth today. Of these, four thousand are mammals. Only one among the four thousand experiences significant blood loss on a regular basis. If conception does not occur, a fertile human female sheds the lining of her uterus along with approximately forty to eighty milliliters (several tablespoons) of blood every four weeks. A few other mammals—for example, hedgehogs, bats, shrews, and elephants—show signs of menses, but for all of them it is a relative nonevent. Primatologist Alison Jolly estimates that there are approximately 270 different species of primates.4 Only thirty-one species of primates menstruate. All of these but one, a human, lose an insignificant quantity of blood.
Blood is an essential fluid. What conceivable benefit could female blood loss have conferred on the survival of our species? Something as dramatic as monthly menstrual bleeding must somehow be accounted for in the evolutionary scheme of things.
Although it is possible that menses is an incidental spandrel related to some other adaptation, it looms so large as a constant in the life of every woman that it is unlikely to be a mere accident of nature.† (The point raised by some anthropologists that ancestral women rarely menstruated because they were either pregnant, lactating, or menopausal will be addressed in detail in a later chapter.)
Adding to the enigma of human menses is the human females’ propensity to coordinate their menses with other women, a feature rarely observed in nonhuman primate females. Like the tines of disparate tuning forks all resonating to the same note, women involuntarily tend to synchronize their periods when they live or work together in offices, convents, dormitories, and large families. Ancestral women lived in tight-knit clans numbering around twenty to thirty fecund women. It is likely that these women, too, synchronized their periods. One suspects it is a very old adaptation that once served an important function in our species’ development.
An unexpected component of human females’ synchronized menses is that the conductor orchestrating this harmony is an inert 81,000,000,000,000,000,000-(eighty-one-quintillion) ton object located 250,000 miles out in space. The moon is the metronome that sets the tempo for cycles that begin to vibrate in unison in the dark interiors of billions of women’s pelvises each month. It is likely that ancestral women, too, entrained their menses with the lunar orbit.
During the past century, technology has flooded our lives with artificial light. Fluorescent and electric lightbulbs have illuminated what had previously been darkness. Moonlight is no longer the critical illumination it once was. Most people are unaware of the current status of the moon’s phases. Yet most women continue to coordinate their menstrual cycles with lunar ones.
Another anomaly of the human female’s sexual life cycle is her menopause. A woman stops ovulating at an earlier point in her life than any other female mammal, while coincidentally acquiring the distinction of becoming the longest-lived terrestrial mammal.* If she avoids maternal mortality and other causes of an early demise, a woman can on rare occasions achieve a life span exceeding a hundred years. The human female was clearly built to last.† At present in the United States, she outlives her male counterpart by an average of six years, while attaining an average life span of eighty-three years.
A postmenopausal woman possesses a longer period of life during which she is incapable of conceiving a new life than any other female mammals, even though she remains quite vigorous for most of these years. With very few exceptions, other mammalian females ovulate right up to the day they die. And a woman stands in stark contrast to a man, who, despite advanced age and many infirmities, usually can generate viable sperm far into his dotage. Another baffling feature of human menopause: Despite the early cutoff in their reproductive faculty, some menopausal women report an increased libido.5 If the purpose of sex is the continuation of the species through reproduction, why, only in the human line, did early cessation of ovarian function combine with longevity and increased libidinous desire?
The innovations distinguishing the human female from other mammalian females mentioned thus far pale when compared with her most spectacular new feature. She became the first female of any species who possessed the willpower to refuse consistently to engage in sex around the time she was ovulating. For that matter, she was the first animal of either sex, of any species, capable of deciding to remain celibate if she so desired.
This resolve is at the heart of Response W. This is the gift Natural Selection bestowed upon her for having to endure Factor X, high maternal mortality and painful childbirth. It is something that had heretofore never existed in the animal kingdom. Philosophers call it Free Will. And herein lies the crux of relations between the sexes. African Eve and her daughters developed the determination to choose consciously a course of action that overrode the instinctual circuits that drive every other species’ females to copulate when they ovulate. Females of some other species may be able to choose which male among multiple suitors upon which they wish to confer their favors; an occasional female of any species may decide not to mate with anyone or at any time. But the human species was the first in which all the females evolved the capacity to decide consciously to refuse to mate during any one ovulation or all the time.
A major overhaul of the human brain was necessary before a female could acquire the requisite mental equipment to exercise Free Will. The radical new configuration encompassed three key additions. First, when the brains of both men and women rapidly increased in size, they acquired considerable heft. The majority of the new nerve cells were primarily located in the outer covering of the brain, called the neocortex. Second, the frontal lobes, the ones located directly behind the forehead, greatly enlarged. Third, the hemispheres of the human brain became highly specialized. Each half dramatically seized control over opposite but complementary functions. (These three trends can be discerned in earlier hominids’ brains, but they greatly accelerated in humans.)
These unique developments led to the creation of special areas within the brain solely dedicated to human language, facial recognition, musical appreciation, rationality, and self-conscious thought. Once activated, the presence of novel mental skills allowed the possessor of one of these new turbo-charged brains to override the circuitry that demanded obeisance to the sexual urges. Unexpectedly, the female of the human species gained considerably greater control over these basic urges than did the male.
She developed an ego-consciousness capable of disengaging from the be-here-now mentality used by all other animals. There came into existence within her brain “a room of her own” high above the hurly-burly of her insistent instincts and hormones. For the first time ever, a female had the time to reflect in depth on the consequences of mating. She became the first female of any life-form to understand the connection between sex and pregnancy. Among the grunting, heaving, thrusting biomass of creatures periodically engaging in sex, it is extremely doubtful that any one of them has the faintest idea what this strange activity’s ultimate purpose is.*
To make the connection between the pleasure of sex and the intense, painful contractions of childbirth nine months later, an ancestral woman needed to become aware of time. “So that’s what caused my belly to swell,” mused the first female who figured out this essential link. Her crucial insight marked a sharp line between all the organisms that had evolved before this event and the solitary one that evolved after it. The new Homo sapiens female acquired the ability to arch over the present in order to connect the past with the future, a skill that does not exist to su
ch an extraordinary degree in the mind of any other animal.
Haltingly at first but with increasing assertiveness, this new female was finally able to refuse the hard-wired commandments that demanded she mate when she ovulated. The first woman who achieved such veto power must have mumbled, in the proto-language in use at that time, the equivalent of “Free at last, free at last.”
To many women, the most liberating sexual event in history was the invention of the Pill. However, 150,000 years earlier, women acquired a more important advantage: the resolve to say No! The story of her release from the slavery of brute instinct is the preface to the tale of how modern humans, both men and women, came to be the way we are. Homo sapiens means “Wise Man.” So much greater were the changes in the female of the new species than those of the male that it would have been more accurate for scientists to have named our genus and species Gyna sapiens rather than Homo sapiens.† Throughout the rest of this book, I will acknowledge what I believe to be these most critical adaptations by using Gyna sapiens when referring to the ancestral females of the species Homo sapiens, genus Homo.
The female—not the male—underwent a major transformation, because it was the female—not the male—who was dying in childbirth. It was the female—not the male—who confronted an evolutionary crisis. The dictates of Natural Selection would predict that she, rather than he, would evolve novel adaptations to the challenge. By wresting control away from her sexual urges, Eve and her daughters exerted discipline over the process of conception. It was small compensation for the increased risks she exposed herself to whenever she became pregnant. If she was to be the one who died in childbirth, then it was she who had best be able to choose when, where, how, and with whom she would become intimate.