We often hear expressions of surprise at the special status accorded athletes in our society. Why, a commentator might ask, should we look up to someone because they can hit a baseball, run exceptionally fast, or bend a soccer ball around a wall of defenders? Some find it surprising that even single events of athletic prowess can touch such a wide swath of society as to inspire an almost religious reverence.

In our waking hours we are constantly assaulted by outside forces that seek to destroy us: predators, parasites, microbes, poisons, and even fellow humans. Our bodies respond with formidable defenses, though at considerable cost. As we fight for survival, we overuse and damage our muscles; we exhaust our neurons, expending their biochemical reserves while at the same time building up toxins; we struggle to cope with a relentless onslaught of information that we feel, rightly or wrongly, must be assimilated to ensure our survival; we fight pathogens of various sorts that attempt to parasitize our blood or eat our skin. Our own species members are if anything even more dangerous: enemies threaten our status, income, and even our very lives. By evening we crave time to gather our thoughts and make sense of our experiences; we need time to repair the daily ravages that have diminished our bodies. We need an opportunity to rest and regroup. Sleep is that opportunity. Without it we would, quite literally, die. It is a daily chance to reverse all the insults our physical and mental being has suffered during the day and to assemble our resources to face another day.

Paleontologists are a contentious lot. Consider the simple question “How many species are there in the genus Homo?” Paleontologists cannot agree. When it comes to more complicated problems all hell breaks loose. Why did the traits that most characterize our species evolve? What drove the evolution of big brains? Of hairlessness? Of language and pair bonding? Ask 10 paleontologists and you will get 10 answers.

Jane Goodall had hardly been at Gombe for a year when, in 1961, she made perhaps the most stunning revelation in the history of primatology (Goodall, 1968, 1971): that chimpanzees hunt and eat meat. It had been assumed that hunting and meat-eating were unique to humans, and indeed many scholars felt the demands of hunting were the unique selective pressure that led to the evolution of humanity, a viewpoint definitively articulated in the influential book Man the Hunter (Lee & DeVore, 1968). Speech, these researchers maintained, was critical for coordinating the swarm of hunters as they pursued herd animals; stalking prey was thought to require keen logic and a thorough knowledge of animal behavior, including the ability to make complex calculations about the escape routes of fleeing game and how best to overtake them as they maneuvered across a complex landscape. The use of tools, a critical cultural practice for humans (it was thought), emerged to enhance the ability of humans to dispatch and then butcher prey. The distribution of meat after a successful hunting foray was assumed to draw on every unique human intellectual resource, since it was governed by a complicated set of rules balancing social obligations, needs, friendship, kinship, and the responsibility of discharging debts from previous meat distributions. The extra calories from animal protein hypothetically allowed large social groupings. The large human brain could not exist without the abundant protein and fat in meat, otherwise extremely rare in nature. Human-style predation, Man the Hunter reasoning went, was the ecological niche for which nearly every unusual aspect of humanity was evolved.

The centuries-long discovery of the chimpanzee, its ecology, anatomy, and behavior, has consisted of a slow-motion, step-by-step revelation that humans and chimpanzees are more, then still more, then still more similar than expected. Yet this reversal has its origin in the perception that humans were a thing apart with respect to other species. Humans and chimpanzees, despite their micro-similarities, have macro differences as well; chimpanzees have fur; their arms are longer than their legs; their brains are smaller.

Primates as an order have a long period of infant dependency, and chimpanzees have among the very longest; females dedicate five years, on average, to seeing a baby through to weaning, a colossal energetic investment and – in a species in which the female lifespan is 45 (Hill et al., 2001) – a stunningly large chunk of a female’s reproductive life. With infancy extending to half a decade, it is probably no surprise that among chimpanzees the strong and resilient bonds forged in infancy continue well beyond that. For a few lucky mother–offspring pairs, they last the rest of a mother’s life, sometimes evolving into a sort of partnership, as they did for Fifi and Fanni, two chimpanzees at Gombe (Figures 16.1–16.3).

We have known that chimpanzees exist for centuries (see Yerkes & Yerkes, 1929 for the definitive review of great ape historical scholarship; also, Reynolds, 1967; Hill, 1969; Goodall, 1986). In the course of that time they have been discovered, rediscovered, confused with humans, confused with orangutans, portrayed as mythical monsters, and transported across seas merely to amuse royalty. Many of them ultimately achieved a sort of immortality as museum specimens.

Long ago, before the invention of many things that are so much a part of our daily lives that we take them for granted – before bicycles, matches, trains, the canning of food, and the invention of flight – we had in our hands a thorough record of chimpanzee anatomy (Tyson, 1699; Brockman, 2000). As improbable as it seems, Western science first confronted the astounding particulars of chimpanzee anatomy over 300 years ago with the publication of Edward Tyson’s brilliant monograph documenting his dissections (see Figure 7.22 for an illustration from the book).

Paleontologists face challenges seldom encountered in the scientific world. Their task is to put flesh – and behavior, if possible – on the bones of long-dead animals. Yet rarely do they have more than a handful of fossilized scraps. True, now and then a joyous cry echoes through the halls of academe as a half-skeleton of some important primate species is announced, but such rapturous events are rare. Instead, a typical haul is a chipped-up elbow or an inch or two of jaw with a tooth or two. Nature seems almost to be plotting against us.

Imagine the workings of a factory (Figure 15.1). The X-Cell-O corporation produces building materials, everything from steel beams to iron roofing to windows – the same sorts of material, in fact, of which the factory building itself is made; in a way we could almost say it reproduces itself. Iron ore and scrap metal are trucked in and shunted to the blast furnace, where they are melted. Impurities are skimmed off before the molten iron is poured into molds; the still-soft molded steel is then pressed between rollers to produce a thin sheet, much as dough is rolled out with a rolling pin. A series of rollers might shape some of the still-glowing, malleable steel into I-beams. Metal sheets are sent to stamping machines to shape them into window frames or iron roofing sheets. Finished products are shuttled to the dock for pick-up.

We probably understand chimpanzees best of all the apes, and possibly best of all primates. Six wild studies have gone on for 55 years or more (McGrew, 2016), and three times that many have gone on for decades.

The startling contrast between bonobo and chimpanzee societies comes into sharp focus in a story Nahoko Tokuyama tells of the intemperate eagerness of a quartet of young males and the rigid social control several females exercised to restrain them (Angier, 2016). It was in the evening, past the time bonobos normally have settled into their sleeping nests for the night. A female was in estrus her flamboyantly swollen estrous swelling stimulating an unrestrained sexual excitement among four males, including the community’s alpha male. Perhaps these males suspected they were skirting the edges of societal norms as they noisily leapt from branch to branch around the female, displaying erections and disturbing what should have been a time of quiet repose for the group. The males, however, were not interested in repose; the presence of this attractive female was simply too much for them to bear. Their overheated commotion went on and on, seemingly with no end in sight. At last, three high-ranking females had had enough. Exploding from beneath, they attacked the four males, scattering them and then ignominiously banishing three of the four into the night, each yelping in retreat. They surrounded the fourth, the alpha male, seized him, and, ignoring his screams of panic, bit him repeatedly – part of a toe was bitten off completely. As the attack wore on he was at last able to break free from the females and flee into the darkness. He failed to reappear the next day, and the day after that; then his absence extended for an entire week. In fact, he limped back into the group only three weeks later, short both a bit of dignity and a bit of a toe.

If we could transplant your brain into the skull of a chimpanzee so as to allow you to experience the world through their sensory system, you would see things … just as you do now. Chimpanzee and human senses are so similar that your vision, touch, taste, smell, and hearing would be so little different you would hardly notice. As unalike as our bodies appear at first sight, the data the chimpanzee body sends to the brain are virtually identical to ours.

If you were asked to say how similar human and chimpanzee technology is, your mind’s eye might drift toward an image of a chimpanzee grasping a straw-like termiting stick or cracking nuts with a stone hammer. You might choose an airplane or a car to represent human technology. This comparison shows up chimpanzee cultural objects as profoundly simple, but we should keep in mind that our current level of sophistication, even many of our simplest tools, is of recent origin. This is an unfair comparison.

While it has been decades since scholars accepted that humans are not the only tool makers and users, contemporary scholarship seems less aware that, after humans, chimpanzees are by far the most inveterate tool makers and users in the animal kingdom; they use tools more than all other primates combined (McGrew, 1992, 2010). Alone among the primates, humans are considered to be dependent on hunting vertebrates to survive. But what does that mean? If an entire human population was exposed to Alpha-Gal and became allergic to meat, would it wither and die? Perhaps people would reproduce more slowly and the population density would decrease, but would every person inevitably die? Unlikely. Consider chimpanzees, then. They hunt once a week and most populations depend on meat to fill a substantial part of their nutritional needs. They could live without meat, but it probably helps sustain their population size.

An extraordinary experiment conducted by Emil Menzel (Menzel, 1971, 1973, 1979) revealed the sophistication of chimpanzee nonverbal communication as none had ever done before. He picked a single chimpanzee from his research group and, out of sight of other group members, walked him around an outdoor enclosure, hiding food as he went. This “knower” was then returned to the social group to interact with other chimpanzees. Menzel then released the entire group into the enclosure. The group rushed into the enclosure in a fever of excitement, anticipating retrieving highly desirable treats and quickly found them. Incredibly, sometimes the knower was not the first to reach the treats. Others ran ahead to find it first.