the kinds of danger that would have made sharper hearing necessary for ground-dwelling species.
Of all primate physiological functions, Darwin seems most intrigued by the vocal prowess of some monkeys and apes, particularly the “singing gibbon,” whose long calls are more powerful than any human voice, even that of a trained opera singer. Gibbon calls, remarkably, travel farther even than the long calls of gorillas and orangutans. One gibbon, the Hylobates agiles, Darwin notes, can reproduce an entire octave of musical notes, “which we may reasonably suspect serves as a sexual charm,” just as music functions in the human species.19 (Curiously, W. C. L. Martin, one of Darwin’s sources, reproduces the call in musical notation.) Many simians, Darwin remarks, are musical and convey emotions by tonality, as Poe anticipates when his witnesses to the murders in the Rue Morgue comment on the orangutan’s supersyllabics and tone. Darwin thus believes that most primate calls function as communications of important information about the individual’s surroundings or emotional state, or they serve as a kind of vocal ornamentation in reproductive competition among males. But among the New World species studied by Rengger, both sexes of some howlers evidently sing because “they delight in their own music and try to excel each other.”20 In this way, Darwin speculates, monkey calls are probably similar to the music and poetry of archaic humans. Ever intrigued by sex, he proposes that in humans singing evolved before speaking—because it added sex appeal and could express emotion as well as information.
Darwin also devotes a great deal of space to the limbs and extremities, but unlike Huxley, he explains function along with anatomy. Darwin’s investigations lead him to believe that evolutionary pressures among the various primate species have resulted in hands specialized for climbing (monkeys and apes) or refined manual dexterity (humans), but it is physically impossible, he theorizes, for a hand to be perfectly suited for both. Likewise, Darwin considers legs, feet, and toes as they have adapted to locomotion, concluding that bipedalism, an adaptation to open spaces, would be maladaptive in arboreal environments, where food, shelter, and safety depend on ease of movement in trees. He suggests that human bipedalism initiated a cascade of other adaptations—feet that support weight, a spine curved for balance, a broadened pelvis. Bipedalism also freed the hands, making powerful jaws and large teeth unnecessary as weapons and even less important for chewing, since food could be manually modified.
But Darwin stops short of relating increased intelligence and capacity for speech to bipedalism, as some more recent evolutionary biologists have suggested. In his view, human mental powers originated in primate social life in all its dimensions. Indeed, almost everything Darwin has to say about primate morphology, bodily functions, and senses is connected to speculations about behaviors shared by humans and their cousins, the apes and monkeys.
Like most twentieth-century primatologists, Darwin be-lieved that the behaviors most clearly connected with physiology are reproductive. In his view, sex is so central to male primate experience that nonhuman male primates demonstrate an ability to distinguish females of other species from the males. In the second edition of The Descent of Man, Darwin added an account of a male mandrill at the zoo who attempted to bully women visitors into mating. Evidently figuring his best chances for reproductive success, “he was by no means aroused with so great heat by all. Always he chose the younger and picked them out in the crowd and summoned them by voice and gesture.”21 This anecdote evidently so em-barrassed Darwin that he not only placed it in a footnote but wrote it in Latin; presumably, women, who were seldom trained in classical languages, would not be able to read it. (Without denying this particular mandrill’s behavior, I must point out that recent studies show that nonhuman male primate sexual behavior is more often a response to female readiness and that older females are generally more popular than young ones, who have yet to prove their fecundity.)
In animals that reproduce through internal fertilization, of course, males and females have different organs. But Darwin almost always subordinates his discussions of morphology to speculations about process and function. In most primate species, adult males tend to be larger boned, louder, bigger, hairier, and more colorful than adult females. A South African Little Red Riding Hood might have said “What big teeth you have!” to a strapping male chacma baboon instead of a wolf. The question is why. Darwin suggests that sexual dimorphism is apparently unrelated to family structure, whether monogamy or polygamy, and he observes that both kinds of families have occurred in human communities throughout history. (However, the relationship between sexual dimorphism and social reproductive structures is still debated among primatologists today.) What clearly does matter in Darwin’s scheme is sexual selection—that is, a differential in the ability of individuals to pass on their genes. One determiner of sexual selection is male competition for mates; size and strength are useful in a pitched battle. The size and strength that help an individual find mates also help when males take on the role of defending their female and infant conspecifics from predators—a behavior related to reproductive success insofar as it protects a particular male’s progeny or the progeny of his kin.
Maybe big, strong males are more attractive to females even without a fight, especially if they are handsome and musical. Darwin goes into detail about what makes the males of various species sexy. Male primates tend to have more powerful vocal mechanisms, and in most primates with throat pouches, the males’ are bigger than the females’—if the females have them at all. Darwin interprets this feature as an advantage in battles among males for sexual access; as a sexual attraction to females; and, in some species, as an aid to the male in fulfilling his responsibility to protect the females of his group and their young. Likewise, Darwin interprets the large canines and sagittal crests, or cranial reinforcements, of gorillas as defensive advantages that come into play most often during competition for, or protection of, mates. He explains the beards of human males as sexual ornamentation and the relative hairlessness of human females in terms of sexual attractiveness. Similarly, in a long and charmingly illustrated discussion of sexual dimorphism in monkeys, Darwin interprets various puffs, crests, points, and contrasting hair colors in male capuchin, spider, and langur monkeys as sexual ornamentation, useful in attracting females, who are in many primate species the chooser rather than the chosen. Darwin notes the similarity between simians and humans: “Man is more powerful in body and mind than woman, and in the savage state he keeps her in a far more abject state of bondage than does the male of any other animal; therefore it is not surprising that he should have gained the power of selection.”22 This belief accounts for the circular logic implied by the “pornographic” Latin footnote and critiqued by feminists of Darwin’s own time and place: women are not as intelligent as men and therefore should not be trained to read Latin; then, their inability to read Latin suggests a lower degree of intelligence. Darwin was a revolutionary, but he was also a man of his time.
Although Darwin’s science went against the grain of many Victorian prejudices, it was so much a product of the time that his argument on sexual dimorphism in humans is not only anthropocentric and Eurocentric but more convoluted than most of his other work. In this section of his analysis, which covers not geological time but historical time and geographic location, modern civilized women are said to have “evolved” ornamentation by stealing bird plumes and other artificial body extensions to attract men. Humans are therefore different from other primates in the operation of sexual selection. According to Darwin’s theory of sexual selection, in the rest of the primate world (with a few exceptions), males are larger than females because they must fight one another to vanquish rivals and impress the females, who then choose to mate with the victors. The relatively large size of human males cannot be explained in these terms, he claims, because men no longer fight over women. In spite of his diligent research into the reproductive habits of other primate species, Darwin is reduced to special pleading: human males have inherited their relatively large size “from some early male progenitor, who, like the existing anthropoid apes, was thus characterized.”23
Darwin was a poetry lover in his youth and packed Milton in his bag before boarding the Beagle. Nevertheless, he seems to have overlooked the significance of the Victorian fad of inventing and reinventing an epic past in literature, art, architecture, and even home decorating, with fictional heraldry placed above
