CHAPTER FIVE

How Our Ancestors Transgressed the Boundaries of Apehood

It has long been known that humans resemble monkeys in interesting ways, but nineteenth-century Europeans innovatively began to interpret that resemblance as a trail of common descent, literally a family resemblance. There are two groups of animals living in the Old World that are especially similar to our own genes and bodies. The more distant are known as monkeys, and their bodies are built for a four-legged gait, walking on branches and the ground, with their fingers extended and with a long spine, ending in a tail of variable length. The other group is known as apes, and its members are built for hanging from branches, suspending themselves. Their shoulders move differently; their hands while in the trees are like hooks, and when they come to the ground, their fingers are flexed, to varying extents. And since they spend a lot of their time hanging in a nearly vertical posture, they use their spine differently, and it is shorter and stiffer than a monkey’s. By the eighteenth century, the French naturalist Count de Buffon could complain that English possessed an advantage over French in making that crucial distinction:

The English are not reduced, as we are, to a single name for the singes; they have, like the Greeks, two different names, one for tail-less singes, which they call “ape,” and the other for the tailed singes, which they call “monkey.”1

Our anatomy places us among the apes, as we have a similar shoulder and a short, fairly rigid spine. Our genes link us especially to those animals as well. Yet we are obviously different from the apes, in speaking, striding, and cooking, as well as in less archaeologically detectable—but possibly just as important—ways, like pointing, sweating, and following rules. It was Darwin who recognized that the best explanation of the physical similarity was as a trail of common descent (as the early philologists had appreciated about the similarities of languages from Ireland to India, a half century before The Origin of Species²).

Phylogeny and classification are different things: one is history; the other is language. One may be based on the other to greater or lesser extents, but they are different classes of facts. As we noted in chapter 1, the question of your relationship to your ancestors—Are you simply them?—is a highly biopolitical question. From the standpoint of racial ancestry, for example, your identity and your ancestry are governed by a set of cultural rules: that the categories are discrete (“racialism”); that they are deterministically associated with social, political, and economic differences (“racism”); that a little bit of lower-status ancestry overrides the higher-status ancestry (“one drop of blood”); that if you are biracial, you assume the identity of the lower-status race (“hypodescent”). Are you reducible to the properties of your ancestors (“hereditarianism”), or can you somehow be free of them? Can you be more than they were? Can you be just simply different from them?

The answer to that last question is obviously yes—after all, that is what we mean by evolution, the fact that descendants are indeed different from their ancestors. In a basic sense, then, if someone were to say, “We are apes,” that statement might be construed to mean, “We have not evolved,” for it fails to acknowledge the naturalistic production of difference between ancestors and descendants. In the very first book on human evolution, Thomas Huxley explained, “No one is more strongly convinced than I am of the vastness of the gulf between civilized man and the brutes; or is more certain that whether from them or not, he is assuredly not of them.”3 Huxley is explaining why you can be from the apes (ancestry), yet not be of them (identity), for you have evolved. Nearly a century later, the paleontologist George Gaylord Simpson made the same point: “It is not a fact that man is an ape, extra tricks or no. . . . Such statements are not only untrue but also vicious for they deliberately lead astray enquiry as to what man really is and so distort our whole comprehension of ourselves and of our proper values.”⁴

Nevertheless the idea that we are an ape of some sort—that our identity, rather than just our ancestry, is that of an ape—is a common theme in the popular scientific literature. Asserted in such science best sellers as The Naked Ape and The Third Chimpanzee and Why Evolution Is True,⁵ the assertion is a simple falsehood that miseducates the public, if we are to give any weight to the explanations and judgments of Huxley and Simpson.

The most recent assertion that “we are apes” is derived from the demonstration of our intimate similarities to the apes genetically. That, however, is simply a bias of the nature of the comparison: we don’t know how to identify bipedalism, language, a chin, sweat glands, small canine teeth, morality, or any of the many and profound differences from the apes genetically. The genetic comparison reveals our ancestry more readily than our difference. As Huxley and Simpson would have argued, if you can’t see our differences from the apes in a genetic comparison, why not simply look at something else?

In the present context, then, given that our ancestry is ape ancestry, it does not follow that we are apes. It could only follow if we arbitrarily gave special privilege to the data that reveal ancestry the most clearly, or if we arbitrarily reduce your identity to simply your ancestry. The “pop science” origin myth of human evolution observes the genetic intimacy of humans to apes, applies the cultural assumption that genetic relationships are the most important relationships, and concludes that our identity can be easily established from our ancestors. But as we noted in chapter 1, the fact that your ancestors may have been peasants or slaves does not make you a peasant or slave. We find the cultural idea of reducing identity to ancestry to be morally repugnant. The reason is simple, that we are different from our ancestors, and our identity is established dialectically, recognizing that we are simultaneously both composed of their DNA and yet different from them.

The genetic intimacy on which the argument that “we are apes” is based was actually known in the early part of the twentieth century. The phylogenetic distance of the Asian orangutan from the African cluster of human-chimpanzee-gorilla was explicitly understood and presented to first-year college students in Earnest Hooton’s classic text, Up from the Ape (1946). When it was rediscovered in the 1960s, it encountered a more favorable cultural climate, in the age of molecular biology and genomics.6 To privilege genetic relationships over other kinds of relationships, as a simple reflex, was a consequence of the “genohype” that accompanied the Human Genome Project toward the end of the twentieth century. It is not the case that DNA comparisons encapsulate species comparisons; if it were, then the fact that our DNA is statistically constrained to match the DNA bases of asparagus at least 25 percent of the time (since there are only four bases in DNA, after all) would imply that we must see ourselves as one-quarter asparagus. Anyone who tells you such a thing is either messing with you or deranged; our DNA simply does not readily translate into a comprehensible identity for us.7

Moreover, to decide that we are simply reducible to our ape ancestors of 8 million years ago, even though our more recent ancestors evolved the abilities to walk and talk, hardly does credit to our fish ancestors of 400 million years ago. Why are we not fish, even though our ancestors evolved the ability to breathe air, and four limbs to support their body weight on land? We fit within the category “fish” phylogenetically, just as we fit within the category “apes”—albeit far more remotely in our ancestry. We can certainly learn something from the recognition of our ancestry, ape or fish,⁸ but that is quite different from saying this is what we are.

If we are not apes, then what are we? We are ex-apes, just as we are ex-fish. Obviously, we are more similar to apes than to anything else. We are both similar to them and yet distinct from them. To emphasize the similarity to apes would lead to a classification proposed by geneticists, who would make chimpanzees another species within our genus, Homo.⁹ To emphasize the divergence would lead to the classification of early anatomists, who separated us from all the other primates at the level of the Suborder, as “two-handed ones” or Bimana.¹⁰ Our compromise, seeing humans and apes as parts of the same Superfamily (called Hominoidea, or hominoids, meaning “rather like humans”), comes from the 1945 classification of mammals by the paleontologist George Gaylord Simpson. A similar compromise juxtaposes the large-bodied apes (orangutan, chimpanzee, and gorilla as Family Pongidae, or “pongids”) to humans and their bipedal ancestors (Family Hominidae, or “hominids,” meaning “even more like humans”).11

In the last decade or so, as the spirit of intellectual compromise has receded in the face of genomics, some scholars have reduced the difference between apes and humans to a lower level, if not quite so low as the geneticists who want to separate us from chimps at the species level. This would break up the great apes and separate us from them below the Superfamily, below the Family, and even below the Subfamily, instead separating us at an obscure level, the Tribe. Here, humans and their bipedal relatives would be called the Tribe Hominini, or “hominins,” meaning “incredibly similar to humans.”¹²

Calling humans and their fossil relatives “hominins,” though, is thus not based upon any new discoveries, but rather upon the application of the contestable cultural assumption that genetic similarities are more important than cognitive, social, or physical differences. This affords a window on the bio-cultural nature of anthropological systematics, in which the number of species identifiable within the genus Homo may be as low as two (erectus and sapiens) or as high as fourteen (antecessor, georgicus, pekinensis, floresiensis, neanderthalensis, gautengensis, habilis, ergaster, rhodesiensis, cepranensis, rudolfensis, helmei, erectus, and sapiens, not to mention Denisovans¹³). We sometimes call scholars who group many fossils into a few species “lumpers,” and scholars who group a few fossils into lots of species “splitters.” But this is not capricious (as the distinction between “lumpers” and “splitters” tends to imply); rather, it is strategic, for there are professional payoffs for “splitting.” After all, more species means more key specimens, and more key specimens means more important people controlling them. And “splitting” enables Spain, Georgia, China, Indonesia, South Africa, Kenya, Zambia, and Italy each to have their own species, and thus each be a key player in the unfolding scientific narrative of human origins.

TABLE 1 Contrasting classifications of living humans and great apes

Species here are not “natural” units, but “natural/cultural” units. They are not built up from facts of nature, but are made as well from the concerns and interests of the classifier, who works partly according to the cultural mind-set and issues of the age. One major scientific concern today is conservation. Most primate species are threatened in the wild. Legislation written to protect them has tended to focus on species. It may be in corporate interests, then, to define the range of a species very widely, so that they can cut down the forest over here, but there will still be some members of the species left over there. And to restore the spirit of the law, we declare that the primates over here are a different species from the one over there, and they are both endangered. That’s why textbooks twenty-five years ago said there were about 170 species of primates, but textbooks today say there are over 400. We haven’t discovered many new ones, and they aren’t speciating like mad. But they are multiplying. Most of the “speciation” is really the recognition that two groups of animals that had previously been considered subspecies, races, varieties, or local populations ought now to be considered as separate species.14 We universally accept that conservation is the most important issue facing both primates and primatologists. After all, without primates there can be no primatology. It is simply far more important to preserve them than to tally them up. So the primates win, the environment wins, and all we have had to do is subtly reconceptualize a species from a unit of evolution to a unit of conservation. This is known as “taxonomic inflation” and is not limited to primate taxonomy. To understand it, you have to realize that a species is not a unit of nature, but a unit of nature/culture or bio-culture. You can certainly argue about what you think a species is or ought to be, but eventually you run into the fact that it is quite simply more important to save the primates than it is to count them—except, perhaps, to some kind of heartless pedant or corporate shill.

The point is that fossil hominid species are products of nature/culture, and so are the living primate species. It’s not that there is no reality; it’s just that the nature of reality is different from what you may have thought it was.

These are not scientific facts whose true qualities could be discerned by a truly objective observer, someone who could manage to free themselves of the confounding effects of culture, and see the world clearly. Thomas Huxley suggested pretending that you’re from Saturn. Jared Diamond, many years later, suggested pretending that you’re from Mars. This is, of course, no science argument at all, but a science fiction argument, built to reinforce the unexamined arrogance of ethnocentric scientific judgments. Those scholars had no better idea about how extraterrestrials would think than you or I do. Indeed, they may have had less of an idea, since they seem to underestimate the diversity of ways and criteria that terrestrial human societies use to classify things.

More interesting, however, is the implicit assumption about the relations between the objective world of nature and the subjective world of culture; it presumes that culture is like the icing on a cake, which needs to be scraped off to reveal nature underneath it. But what if, instead, culture were not like the icing on the cake, but like the eggs in the cake? What if it is impossible to be a scientist outside of culture, external to its assumptions, metaphors, prejudices, and priorities? Then perhaps the best you can do is to try to be as self-analytic as possible, identify the biases of your predecessors, and try to transcend your own.

This is a much more real situation in the study of human evolution, because human evolution is our origin narrative, and such narratives universally have cultural salience. Trying to navigate through the primates in his monograph on mammalian classification, George Gaylord Simpson sighed in print,

Perhaps it would be better for the zoological taxonomist to set apart the family Hominidae and to exclude its nomenclature and classification from his studies.15

HUMAN ANCESTRY

Let us proceed with the assumption that the specific details (such as “Homo ergaster”) tend to be trivial and often short-lived. The bigger picture (at the genus level) is clearer, because the genera represent organisms with different basic adaptations, and which consequently approach their own survival in different ways, which can be identifiable in the paleontological or archaeological record.

Thus, we generally recognize our lineage as beginning with a bipedal adaptation, and ascribed to the genus Australopithecus. This genus has been regarded, since being first described in 1925, as a “missing link” because of its combination of human and simian features. These, most generally, are a brain like an ape’s, yet teeth like a human and the hallmarks of the human bipedal habit. Australopithecus now encompasses material from South and East Africa, ranging from about 4.5 to about 2 million years ago, with the famous fossil “Lucy” falling right in the middle of that range. While earlier material is far more ambiguously bipedal, we find two suites of human-like features in Australopithecus: first, a change in the teeth, from an emphasis on the front teeth (as in apes) to the back teeth (as in humans); and second, a change in the manner of locomotion, from the suspensory and quadrupedal gaits of apes to the obligate bipedalism of humans. This is detectable all through the body, from the base of the skull to the heel of the foot. The brain of Australopithecus, however, is more like an ape’s—only about one-third the size of ours.

In the case of locomotion, moving the head and center of gravity from in front of the pelvis to atop the pelvis, and changing the primary function of the feet from grasping structures to weight-bearing structures, created a suite of subtle, yet diagnostic criteria for distinguishing the body of an ape from that of a human ancestor. The human spine is more curved; the hands are relieved of weight bearing; the pelvis, hip, and knee support the body’s weight, rather than trailing after it; the foot is more stable and less flexible, and the big toe has adjusted for weight bearing rather than for grasping. Even the human skull and neck differ anatomically from the ape’s by virtue of sitting atop the body, rather than ahead of it.16

Yet even for such a fundamental feature as bipedality, we know far more about how it evolved than about why it evolved.¹⁷ We can certainly see the differences it wrought upon ancestral ape anatomy; it was clearly very important. And from the anatomical comparisons, we can tell you how that evolution occurred—what parts of the body changed, and how they changed. And that’s boring, because it’s anatomy. What we can’t tell you is why it happened. That is history, that is origin myth, that is interesting. On the other hand, if a chimpanzee is chasing you to rip your face off, it is going to catch you. You can’t outrun it, because our mode of locomotion makes us a lot slower than an ape.

Presumably being bipedal was good for something, and it had to be good enough to overcome the disadvantage of slowing us down. But we do not know, and quite possibly never will know, because it may be unknowable, exactly what bipedalism was good for. The fact that apes sometimes stand erect when threatening one another, the fact that humans can run longer distances than apes, the fact that having your eyes higher off the ground allows you to see farther—and many others—have been suggested as scenarios for the evolution of bipedalism.¹⁸ That is to say, it must have been good for something. What these propositions all share is the property of futility. If there was an advantage to bipedality, we can’t tell what it was, from our vantage point of 5 or 6 million years later. Consequently we have to side with Isaac Newton, who was challenged on the question of where gravity came from, given that he seemed to have figured out how it worked. “I make no hypotheses,” said Newton; and that should be our guide. We have to bracket the question “Why did we become bipedal?” and set it off from more empirically based scientific discourse on the subject.

We will always be caught in Newton’s trap, however. Once you have figured out how gravity works, why it is there becomes a far more interesting question, albeit an unscientific one. It is the narrative, mythic component of the story; the one far less circumscribed by data and rigorous analysis. Likewise, why we are bipedal is more interesting, but less scientific, than how we got that way. Nevertheless, the very use of bipedalism as an evolutionary marker conceals a shorthand. After all, as we will see in chapter 6, chimpanzees and gorillas can walk bipedally when they choose to. When we talk of the human condition, we are actually talking about the loss of that choice.

The descendants of Australopithecus retained the bipedality and the small front teeth, and evolved in two directions. One, Paranthropus, will rely on the dental adaptation, and will take that adaptation even further, with tiny front teeth and enlarged back teeth and heavy chewing muscles for intense crushing and grinding. The other, Homo, sharpens the hand-eye coordination, increasingly relying on the products of mental and physical labor for survival. The inference of ancestry from Australopithecus is based on the anatomical and temporal continuity that we can identify in the fossil record.19

Homo, by about 1.5 million years ago, has tweaked bipedalism so that the genus possesses our own body proportions, rather than the apishly long arms and short legs of the earlier bipeds. Over its duration, we see a two- or threefold expansion of the skull, and a concomitant increasing sophistication of stone tool types.²⁰ This manner of interacting with the environment, by transforming it and recreating it technologically, is successful enough, even in its rudiments, that Homo settles as well in Asia, and later, in Europe—a range far more extensive than that of Australopithecus or Paranthropus. The fact that this adaptation is based on skills that must be learned, and can be adequately performed in many different ways, suggests that we are dealing with the elaboration of a less accessible adaptation—namely, culture—in which there emerge group-specific ways of doing things.

But let us not abandon locomotion so fast. After all, a human baby isn’t born doing it properly, as, say, an elephant or dolphin baby is. Primate babies often cling to their mother’s fur for a period of time before they even attempt to move around by themselves. But two years before you can actually move properly? That’s a lot to ask of a human child—and, as long as there is a model around to observe, they come through nearly every time, eventually running and walking. Indeed, like our communication system, we are programmed to learn to locomote.

The last human physical features to emerge are our foreheads and chins, detectable by 150,000 years ago, in East Africa. As we will see in chapter 6, the evolution of our species increasingly shifts from the biological to the bio-cultural, and understanding biological evolution helps us understand the human condition less and less. Say what you want about the stories that we call Greek myths, but at least those pagans had an explanation for where fire, for example, came from. It came from Prometheus, as noted in chapter 2, and he paid dearly for it. But that’s more than the Bible says. The Bible doesn’t even try to explain the origin of fire; it’s just there. Nobody has to invent it or discover it or learn to control it.21 But hearths dating back to 300,000 years tell us that our ancestors did learn to control it.

Our ancestors were coloring things by 100,000 years ago (although we don’t know exactly what they were coloring), carving images by 40,000 years ago, and drawing on cave walls by 35,000 years ago. By about 10,000 years ago some humans were living in communities and relying on farming and herding, and controlling their own subsistence. This had many side effects, however, especially of creating wealth, and distributing it (and the power it buys) unevenly among different people. Consequently, although there are still fluctuations accruing to our gene pools, our basic interactions with the external world have shifted over the course of the evolution of our species from principally biological adaptation, like other animals, to principally cultural. This was catalyzed by the emergence of a new way of communicating, about whose origins we have little direct information. This symbolic mode of communication, or language, is based on learning the meaningful associations and divisions among sounds, things, and ideas, which create the new interactions among people, the social conditions of life.

HEADS, WE WIN

The relationship between the head and the mind is a subtle one, and it has led generations of scientists into difficult straits. The brain is inside the head. Aside from Aristotle and his most devout followers (who thought that the brain’s primary function was to cool the body), nearly all ancient and modern European scholars have understood the brain’s primary function to be to produce thoughts. Yet different people have different thoughts—some bad, some good. And some people have mental gifts—for mathematics, for art, for socializing. Is it because they have different kinds of brains? Is it because they have different kinds of heads?

Perhaps we should look to science to find out.

In the first half of the nineteenth century, phrenology, developed by medical anatomists, was one of the most popular applied sciences.22 It answered the question “Why do people have such different personalities?” by recourse to medical anatomy. The logic, primitive if comprehensible, was that people have different personalities because they have different brains; the brain is composed of various modules for music, love, fidelity, and the like, and since the skull encloses the brain, we can read one’s personal talents and abilities from the overdeveloped or underdeveloped parts of their brain, which are inscribed upon the surface of the skull. Just as a home-wrapped Christmas present might contain a bulge for a part that is a bit too large for its box, so too does the skull have bulges corresponding to the overdeveloped parts of the brain governing particular personality attributes. All we need to do, then, is to feel the bumps on your skull, and we can tell you about your latent abilities.

By the latter part of the nineteenth century, this was generally looked upon scornfully by the mainstream anatomical community, which had its own crude logical practice. Just as a large pancreas secretes more insulin, it stands to reason that a large brain secretes more thoughts. Thus, people with large brains are more intellectually gifted than people with smaller brains.²³ One of the strongest early advocates of this idea, Samuel George Morton of Philadelphia in the 1840s, was also a believer in phrenology. And yet, it was not too difficult to find small-brained geniuses and big-brained dummies.

Perhaps, then, the head’s gross shape had something to do with it, in addition to the head’s gross size and surface details, or perhaps instead of them. Some people (and populations) had long heads; others had short, broad heads. Standardized measurements and a pompous scientific vocabulary developed in the middle of the nineteenth century described long-heads as dolichocephalic and broad-heads as brachycephalic. As descriptions of people, of course, they were fine, but as explanations for their histories and social conditions, they were nonsensical, even if scientifically mainstream.24

The early anthropologist Franz Boas began to debunk the value of head shape, for any other purpose than descriptive, by empirically contrasting the head shapes of immigrants with the heads of their children and other family members, and showing that this trait was heavily influenced by the environment.²⁵ On the other hand, the early physical anthropologist Aleš Hrdlička wrote with dismissive condescension about phrenology, but when given the chance to examine the brain of a recently deceased Eskimo (Inuit) from Greenland, he leapt at the opportunity. His 1901 paper, “An Eskimo Brain,” was not followed by “An Eskimo Arm” or “An Eskimo Liver,” so he clearly regarded the organ as one of especially great scientific interest. It is not clear, though, just what he expected to learn from it, although he quite ghoulishly concluded, “The marked differences . . . from those of the whites . . . makes a future acquisition of Eskimo brains very desirable.”²⁶

By the 1920s, it had become clear that culture was not to be found inside people’s brains, but rather, constituted a part of the environment that imposed itself upon people’s brains. This is not to say that all brains are identical, but like arms and livers, their differences are largely irrelevant to the question of why different groups of people behave as they do, or have the histories that they do. In pathological cases, the structure of a brain might be interesting, but it functions pretty much the same way in all normal people, whatever language they speak, and whatever their social background, class, diet, traditions, or values may be.

By the 1950s, the physical anthropologists had come around as well—to the recognition that measuring head size and shape had its uses, but none of them involved the question of why different groups of people think and act as they do. The eventual apprehension of this fact was doubtless a consequence of the fact that the physical anthropology of the Nazis, like their human genetics, was not all that different from its American counterpart, and had to be fundamentally reconceptualized after World War II.27

The head studies, however, required admitting an exception to the guiding principle of anatomy: that form follows function. The new physical anthropology,²⁸ christened by Sherwood Washburn in 1951, would finally follow the cultural anthropologists, and hold as axiomatic that variation in mental properties and functions is disconnected from physical variation in head form. There is a wide range of variation in normal human heads, and a wide range of variation in normal human thoughts, and they map onto one another only in the grossest or crudest of ways. You can’t legitimately infer cultural difference from the observation of cranial difference, nor cultural similarity from the observation of cranial similarity. The reason is that they are epistemologically disconnected, for cultural differences are the products of history, not biology.

Thus, heads are more or less interchangeable across the great bulk of our species, and the brains inside them can do pretty much what anyone else’s brain can do, except in pathological or exceedingly unusual cases. Consequently, when we encounter a modern human skull in the ethnographic, archaeological, or fossil record, we are going to assume that it housed a normal modern human brain, just like yours and mine, and consequently was capable of thinking the full range of normal modern human thoughts, just like yours and mine. That seems to be the best inference we can draw from two centuries of studying the anthropology of heads.29

SYMBOLIC VOCAL COMMUNICATION, OR LANGUAGE

Physical anthropologist Wilton Krogman wrote a classic article in 1951 for Scientific American called “The Scars of Human Evolution.”³⁰ It explained how bipedalism, the defining trait of our lineage, compromised with our bodies. In other words, bipedalism was so central to becoming human that it outweighed the negative consequences it brought with it—like scoliosis, back pain, hemorrhoids, varicose veins, and birthing complications.

Hard as it may be to believe, the evolution of our other most basic adaptation—our symbolic mode of communication, or language—is undertheorized. Language, which is coterminous with symbolic thought—if you can think it, you can say it—was also an unusual and apparently very good evolutionary innovation. And like bipedalism, it was so good, indeed, that it created physical problems that the human body had to solve secondarily in order to make it work, and to some extent never did solve fully.

First, it expanded our heads. Symbolic communication requires a big brain, as well as an extended period of immaturity in order to learn how to do it properly.³¹ It is so difficult that we hardly even appreciate how difficult it is. From the bottom up, we learn what sounds make sense. Are “s” and “sh” variants of the same sound, or different sounds? What about “l” and “r”? Or “r” and “rr”? Or the “Ch” in “Chanukah” or the “Zh” in “Zsa-Zsa”? Are they their own sounds, or some weird variants of “Hanukah” and “Cha-Cha”? If you use that sound, you’re not from around here, or you at least recognize the word that contains it as not being one of our own words. What about the “sh” sound in “shibboleth”? Recognizing that sound—as opposed to hearing it as a variant of the “s” sound—might be the difference between life and death. It meant a lot to the ancient Hebrews, at least—Judges 12:6 tells a story of 42,000 Ephraimites who wished they could have distinguished between those two sounds, as they were being killed off by the Gileadites on that basis. If that sounds too remote, consider the 1937 “Parsley Massacre” in which French-speaking Haitians were killed if they failed to pronounce the Spanish-speaking Dominicans’ word for “parsley” properly.32

We also learn how to combine those sounds, and use them to refer to objects or acts or states. We could call those combinations of sounds “lexemes,” but for the sake of simplicity, let’s just call them “words.” We also learn how to combine those words in meaningful ways—to state, inquire, praise, predict, comfort, recall, amuse, and command, using any of the myriad grammatical forms at our disposal. And on top of all that, we learn intonation, sarcasm, and bodily gestures to go along with the rules of our sounds, their correspondences, and combinations.

In this sense, obviously, our communication is not species-specific, a unitary feature to contrast to a chimpanzee’s communication, but rather is highly local and community-specific in humans. It not only identifies you as a person, but it also localizes you within the category “person,” and generally to a fairly narrow chunk of time and space. The price for all of this was a brain inside a baby’s skull that hardly fits through the birth canal. And the solution to that problem was to make birthing social. While an ape squats and delivers, a human almost always needs to have someone else around.³³

Second, language reorganized our throats. To help make all of those sounds, our larynx is positioned lower down in the throat than it is in apes and babies, who cannot make those sounds. Speech also necessitates far more intricate breath control than apes are capable of.34 The price we pay is that the passage of air into our lungs and that of food into our bellies now crisscross, which they do not in apes, which means that we can choke on our food far more readily than a chimpanzee can. The solution: don’t eat so fast, and try not to breathe while you are swallowing.

Third, language worked over not only our throats and brains, but our teeth as well. Monkeys and apes often have large, sexually dimorphic canine teeth, which they use as social threats and in the occasional actual fight. Classic sexual selection theory holds that in species in which males actively compete for mates, they do so using their canine teeth. In species where there is less competition for mates, because males and female pair off, the males and females have equal-sized canine teeth, as in the more-or-less monogamous gibbons. This is often invoked as evidence that sexual selection has been reduced in the human species, which may well be true. The problem is that those gibbon canines, which are non-dimorphic, are also actually quite large. Ours are non-dimorphic, but small. Why? Quite likely because it is really hard to speak intelligibly through large, interlocking canine teeth. Ask any vampire (or better yet, an actor who has played one). The price for the reduction of the canine teeth was that our canine teeth are not going to intimidate other members of our own species, nor defend us against members of other species. Good thing we started using tools.

Further, it is also not too hard to see how language could strongly mitigate the effects of sexual selection. In most primate species, a big male with big canine teeth can physically dominate not only other males, but females as well. Bonobos circumvent this by having the females become socially and sexually bonded, so that they will gang up against an aggressive male, in the present. Humans have a different solution to the same problem: language permits a victim to name her male assailant, so her friends and relatives can punish him, in the future. A human male who acts like a chimpanzee is much more likely to have to pay for it dearly.

And finally, in addition to reshaping our brains, throats, and teeth, language also reshaped our tongue. To make the sounds we do, our tongue became more muscular, rounded, and enervated than an ape’s tongue. For this the cost was quite severe. An ape dissipates heat, as many mammals do, by panting. But to use your tongue primarily for talking, your body must produce another way of dissipating heat. Our ancestors did that by loading up our skin with sweat glands, for evaporative cooling. But evaporative cooling works most efficiently with bare skin; so our body hair had to get shorter and wispier than that of an ape.

For all that we don’t know about the evolution of language, however, it affords us a critical lesson in human evolution and biology—namely, that “learned” and “genetic” are not antonyms. Language must be considered both “genetically programmed” (for it is the way human beings have biologically evolved to communicate)—and “learned” (for its content is actively acquired over the course of childhood, and sometimes later). This means that the dichotomy of genetic versus learned is necessarily a false one, for language is both. Under the appropriate minimal stimulation (i.e., hearing people speak regularly) a normal human child learns to communicate in this species-specific way, speaking to others. A normal chimpanzee never does; it’s not built to.

Moreover, speech is not simply species-specific; it is also specific to one’s local group. After all, “we” are not just the creatures who speak; we are the creatures who speak in a very particular way. “We” are the people who make the “sh” sound in “shibboleth,” as opposed to our neighbors, the Gileadites; “we” are the people who call a book “book,” as opposed to the barbarians who call it something else, like “biblos” or “sefer”; “we” are the people who don’t distinguish between the “r” sound in the Spanish words “pero” and “perro,” and so they sound pretty much the same to us, even though one means “but” and the other means “dog.” Language is thus not merely a new medium of communication, but also at root a medium of division, a marker of belonging.35

Walking and talking are the two behaviors that are most fundamentally human, and it is quite extraordinary that they rhyme. So the next time you choke, sweat, scream for an epidural, or reach for a weapon to protect yourself because you lack confidence in your teeth to protect you, reflect on the fact that our body parts are interconnected, and that language was such a good way to communicate that it screwed you up in so many other ways. There is a fifth price as well for language: having to listen to people who don’t know when to shut the hell up.