The Great Resculpting

The Face: A Natural History
By Daniel McNeill

(Page 4 of 12)

Few ideas jarred the nineteenth century quite like natural selection. Many thinkers felt an ape ancestry was impossible, even insulting, given our broad minds and deep souls. In one notorious jibe, Bishop Samuel Wilberforce wondered whether evolutionist Thomas Huxley had descended from apes on his grandfather's or grandmother's side.*

Yet suppose apes' faces looked like ours. Would the bishop have ventured this jest? Would fundamentalists be quite so sure Darwin was wrong if they could see the spitting image of themselves beyond the moat in a zoo, calmly stripping leaves off a branch?

Our faces don't resemble those of apes or of any other animal, and it's one reason we've deemed ourselves so singular. Indeed, the recent remake of the human countenance is the most arresting part of its history, and unprecedented in evolution. For our faces stem partly from the products of our minds. Each of us has a smart-face, bred of weapons, fire, and desire.

The steppingstones to humanity lie in Africa. They begin with walking apes, like the famed fossil Lucy, who dwelt in transitional woodlands between 5 and 1.3 million years ago. Known as australopithecines, these creatures looked much like chimps, with their swooping muzzle, chunky teeth, and wisp of forehead.

Yet their upright stance demilitarized the face. A four-legged animal's jaws and teeth reach forward, like a spearpoint, and make the face a natural weapon. A wolf, for instance, lopes along with fangs in front, and even chimps routinely nip their rivals. On two feet, with head poised atop shoulders, the australopithecines not only lost this protective design, but left their whole bodies open to attack.

So how did they fend off the sabertooth cats and hyena packs of the transitional forest? Did they have a vicious kick, like the ostrich and kangaroo? Perhaps they had sharp claws, or wielded wooden sticks. In fact, they probably fled up trees. They were not pure bipeds. Their curled feet and apelike semicircular canals, or balance sensors, suggest they lived part-time in the boughs like chimps. They may have evolved a two-legged stance to cross the ground from tree to tree more quickly.*

The australopithecines lived for eons, but by 2.5 million years ago the globe was cooling and the current pattern of seesaw ice ages had commenced. Africa dried and the trees thinned out, and these creatures may have become easier marks as they raced between them. They dwindled away and a new animal appeared: Homo habilis, the first member of our own genus.

Here was a radically different creature. Homo habilis didn't scurry up trees. It was strictly two-footed. How did it stave off carnivores? It almost certainly used weapons. It could hurl rocks at them, but more significantly, it made stone tools. Some were sharp flakes that could have drawn blood from predators and cut tough hides, possibly letting Homo habilis dine on meat.

Homo habilis was novel in other ways. Its brain grew 50 percent, an astonishing development. And its face began drifting toward the human. Its forehead lifted a bit, its muzzle slimmed, and its teeth shrank, perhaps because they mattered less as weapons. Some had heavy browridges, which anchored the jaw muscles, and the first nub of a projecting nose.

From Homo habilis through Homo erectus to us, the four key changes occur: The face flattens. The forehead rises to house the ballooning brain. The nose juts out. And the chin appears. The first three commenced early, and the chin debuted almost yesterday.

The true human face appeared at the end of a deep ice age 130,000 years ago, with modern Homo sapiens in Africa. It differed strikingly from that of even the Neanderthals, our closest cousins. Indeed, when archeologists want to tell the latter from us, they look first to the face. The Neanderthals had bulging browridges; we just have eyebrows. They had moonlike skulls; ours more resemble short loaves of bread. They possessed long, narrow jaws and massive teeth they apparently used as a clamp. Their noses were great fleshy sodbreakers. They had cavernous eyesockets and virtually no chin. And, notably, they retained a modest muzzle. Our faces are flat.

The vanished muzzle may be the most beguiling evolutionary fact of all. A projecting mouth is essential equipment in almost all vertebrates, from pike to polar bears. It lets them snare, gnaw, and nip.* Yet we don't need it at all. As Darwin suggested in The Descent of Man, our brains made the muzzle obsolete.

A muzzle thrusts teeth outward so they can close like a trap, killing and wounding. Leopards maul prey and camels bite attackers. But our teeth lie within the skull and they make awkward weapons. We manufacture better ones instead, and our hands have evolved myriad grip positions to handle them and other tools.

We also gnaw food less, since we gained control over fire. Hearths first appear around 300,000 years ago, though they don't become common in archeological digs until around 40,000. Cooking softens food, reducing the need for strong jaws and teeth, and if we used fire more than the Neanderthals, it might also explain our loss of browridges.

And we rarely nip our fellows, as chimps do. We fling words instead and the right ones can sting, as witness the Wilberforce-Huxley exchange. They won't stop a grizzly, but they do very nicely with other people. If the muzzle lingered on for nipping, language could have obviated it.

These advances made the muzzle pointless. But it might still have persisted, a genetic free-rider like the appendix. It didn't, and archeologists have wondered why.

The reigning explanation invokes desire, and centers on the allure of the childlike face. We find babies winsome, since ancient folk with this trait paid more attention to their children, raised more healthy adults, and thus spread the gene that makes us google at infants. The attraction carried over to babyfaced grownups. They looked more appealing, reproduced more often, and passed on more babyface genes. The muzzle sank as if punctured and the face came to look infantile. The theory may be right. It's hard to test.

The individuals of 130,000 years ago were anatomical us. They had our foreheads, cheekbones, and flashing teeth, and if we could have looked them in the eye, we would have understood what we saw.

© 1998 by Daniel McNeill

About the Author

Daniel McNeill is a bestselling author and winner of the Los Angeles Times Book Prize for The Face. Mr. McNeill is the principal author of Fuzzy Logic, which won the 1992-93 Los Angeles Times Book Prize for Science and Technology. He has written numerous other books and articles on high technology, and his work has also appeared in fiction, travel, history, law, and education publications. He lives in Southern California.