Read Catching Fire: How Cooking Made Us Human Online

Authors: Richard Wrangham

Tags: #Cooking, #History, #Political Science, #Public Policy, #Cultural Policy, #Science, #Life Sciences, #Evolution, #Social Science, #Anthropology, #General, #Cultural, #Popular Culture, #Agriculture & Food, #Technology & Engineering, #Fire Science

Catching Fire: How Cooking Made Us Human

BOOK: Catching Fire: How Cooking Made Us Human
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Table of Contents
INTRODUCTION
The Cooking Hypothesis
“[Fire] provides us warmth on cold nights; it is the means by which they prepare their food, for they eat nothing raw save a few fruits . . . the Andamanese believe it is the possession of fire that makes human beings what they are and distinguishes them from animals.”
—A. R. RADCLIFFE-BROWN,
The Andaman Islanders: A Study in Social Anthropology
 
 
T
he question is old: Where do we come from? The ancient Greeks told of human shapes being molded by gods out of clay. We know now that our bodies were molded by natural selection and that we come from Africa. In the distant past, long before people first wrote or tilled the soil or took to boats, our ancestors lived there as hunters and gatherers. Fossilized bones reveal our kinship with ancient Africans a million years ago and more, people who looked much like we do today. But in deeper rocks the record of our humanity dwindles until around two million years ago, when it gives way to prehuman ancestors and leaves us with a question that every culture answers in a different way, but only science can truly decide. What made us human?
This book proposes a new answer. I believe the transformative moment that gave rise to the genus
Homo,
one of the great transitions in the history of life, stemmed from the control of fire and the advent of cooked meals. Cooking increased the value of our food. It changed our bodies, our brains, our use of time, and our social lives. It made us into consumers of external energy and thereby created an organism with a new relationship to nature, dependent on fuel.
The fossil record shows that before our ancestors came to look like us, they were humanlike in walking upright, but mostly they had the characteristics of nonhuman apes. We call them australopithecines. Australopithecines were the size of chimpanzees, they climbed well, they had ape-sized bellies, and they had protruding, apelike muzzles. Their brains, too, were barely larger than those of chimpanzees, which suggests that they would have been as uninterested in the reasons for their existence as the antelopes and predators with which they shared their woodlands. If they still lived today in some remote area of Africa, we would find them fascinating. But to judge from their ape-sized brains, we would observe them in national parks and keep them in zoos, rather than give them legal rights or invite them to dinner.
Although the australopithecines were far different from us, in the big scheme of things they lived not so long ago. Imagine going to a sporting event with sixty thousand seats around the stadium. You arrive early with your grandmother, and the two of you take the first seats. Next to your grandmother sits her grandmother, your great-great-grandmother. Next to her is your great-great-great-great-grandmother. The stadium fills with the ghosts of preceding grandmothers. An hour later the seat next to you is occupied by the last to sit down, the ancestor of you all. She nudges your elbow, and you turn to find a strange nonhuman face. Beneath a low forehead and big brow-ridge, bright dark eyes surmount a massive jaw. Her long, muscular arms and short legs intimate her gymnastic climbing ability. She is your ancestor and an australopithecine, hardly a companion your grandmother can be expected to enjoy. She grabs an overhead beam and swings away over the crowd to steal some peanuts from a vendor.
She is connected to you by over three million years of rain and sun and searching for food in the rich and scary African bush. Most australopithecines eventually went extinct but her lineage slowly changed. Evolutionarily, she was one of the lucky ones.
 
 
 
The transition is first signaled at 2.6 million years ago by sharp flakes dug from Ethiopian rock. The fragments testify to cobblestones being deliberately clashed to produce a tool. Cut marks on fossil bones show that the simple knives were used to cut tongues out of dead antelope and to get hunks of meat by slicing through tendons on animal limbs. This new behavior was remarkably effective—it would have allowed them to skin an elephant quickly—and was far more skillful than anything chimpanzees do when eating meat. Knife-making suggests planning, patience, cooperation, and organized behavior.
Old bones continue the story. By around 2.3 million years ago, the first tentative record emerges of a new species, a habiline. Habilines, still poorly understood, are the “missing link” between apes and humans. They were truly missing until 1960, when Jonathan Leakey, the twenty-year-old son of paleontologist Louis Leakey and archaeologist Mary Leakey, discovered them in the form of a jaw, skull, and hand in Tanzania’s Olduvai Gorge. Even now there are only six skulls that tell us the brain size of the principal species, and just two reasonably complete specimens showing their limbs, so our portraits of these intermediate beings are fuzzy. Habilines appear to have been about the same small size as australopithecines and had long arms and jutting faces, leading some people to call them apes. Yet they are thought to be the knife makers, and they had brains twice as big as those of living nonhuman apes, so others place them in the genus
Homo
and thereby call them human. In short, they show a mixture of prehuman and human characteristics. They were like upright chimpanzees with big brains, and we might guess they were just as hairy and almost as good at climbing trees.
After the habilines emerged, it took hundreds of thousands of years for the evolutionary gears to start turning rapidly again, but between 1.9 million and 1.8 million years ago, the second critical step was taken: some habilines evolved into
Homo erectus,
and with their arrival the world faced a new future.
The mental abilities of
Homo erectus
are open to question. We do not know whether they used a primitive kind of language, or how well they controlled their tempers. But
Homo erectus
looked much more like us than any prior species. They are considered to have walked and run as fluently as we do today, with the same characteristic stride that we have. Their various descendants, including Neanderthals more than a million years later, all exhibited the same form and stature. If they time-traveled to a modern city, they might suffer some sidelong glances but they could be fitted for clothes in a typical store. Their anatomy was so similar to ours that some anthropologists call them
Homo sapiens
, but most give these pioneers their own distinct name of
Homo erectus
because of such features as smaller brains and lower foreheads than are found in modern humans. Whatever we call them, their arrival marks the genesis of our physical form. They even appear to have grown and matured slowly, in the manner of modern humans. After their emergence it would be mainly a question of time and brain growth before modern humans emerged about two hundred thousand years ago.
So the question of our origins concerns the forces that sprung
Homo erectus
from their australopithecine past. Anthropologists have an answer. According to the most popular view since the 1950s there was a single supposed impetus: the eating of meat.
 
 
 
Hundreds of different hunter-gatherer cultures have been described, and all obtained a substantial proportion of their diet from meat, often half their calories or more. Archaeology indicates a similar importance of meat all the way back to the butchering habilines more than two million years ago. By contrast, there is little to suggest that their predecessors, the australopithecines, were much different from chimpanzees in their predatory behavior. Chimpanzees readily grab monkeys, piglets, or small antelopes when opportunities arise, but weeks or even months can go by with no meat in their diets. Among primates we are the only dedicated carnivores, and the only ones to take meat from large carcasses.
Those smaller-brained ancestors could not have obtained meat without confronting dangerous animals. Their physical abilities often would have proved wanting. The first meat eaters certainly would have been slow, they had small bodies, their teeth and limbs made feeble weapons, and their hunting tools were probably little more than rocks and natural clubs. Greater ingenuity and improved physical prowess would have helped bring down prey. Hunters might have chased antelope on long runs until the quarry collapsed from exhaustion. Perhaps they found carcasses by watching where vultures swooped down. Predators such as saber-toothed lions brought further challenges. Teamwork might have been necessary, with some individuals in a hunting party throwing rocks to keep fearsome animals at bay while others quickly cut off hunks of meat before all retired to eat in a defensible site. So it is easy to imagine that the rise of meat eating fostered various human characteristics such as long-distance travel, big bodies, rising intelligence, and increased cooperation. For such reasons the meat-eating hypothesis, often called “Man-the-Hunter,” has long been popular with anthropologists to explain the change from australopithecine to human.
But the Man-the-Hunter hypothesis is incomplete because it does not explain how hunting was possible without the economic support gathered foods provided. Among hunter-gatherers, gathering is mostly done by women and is often responsible for half the calories brought to camp. Gathering can be just as critical as hunting because men sometimes return with nothing, in which case the family must rely entirely on gathered foods. Gathering depends on abilities normally considered to be absent in australopithecines, such as carrying large bundles of food. When and why did gathering evolve? What breakthroughs in technology enabled females to gather? Or did habilines get their meat without being involved in an economy of exchange? These are core questions Man-the-Hunter leaves unanswered.
A different kind of difficulty is even more severe: the habilines show that there were two changes in the path from ape to human, not just the one implied by Man-the-Hunter. The two steps involved different kinds of transformation and occurred hundreds of thousands of years apart—one probably around 2.5 million years ago, and the second between 1.9 million and 1.8 million years ago. It makes no sense that the two kinds of change should have been prompted by the same cause.
Meat eating accounts smoothly for the first transition, jump-starting evolution toward humans by shifting chimpanzeelike australopithecines into knife-wielding, bigger-brained habilines, while still leaving them with apelike bodies capable of collecting and digesting vegetable foods as efficiently as did australopithecines. But if meat eating explains the origin of the habilines, it leaves the second transition unexplained, from habilines to
Homo erectus
. Did habilines and
Homo erectus
obtain their meat in such different ways that they evolved different kinds of anatomy? Some people think the habilines might have been primarily scavengers while
Homo erectus
were more proficient hunters. The idea is plausible, though archaeological data do not directly test it. But it does not solve a key problem concerning the anatomy of
Homo erectus,
which had small jaws and small teeth that were poorly adapted for eating the tough raw meat of game animals. These weaker mouths cannot be explained by
Homo erectus’s
becoming better at hunting. Something else must have been going on.
How lucky that Earth has fire. Hot, dry plant material does this amazing thing: it burns. In a world full of rocks, animals, and living plants, dry, combustible wood gives us warmth and light, without which our species would be forced to live like other animals. It is easy to forget what life would have been like without fire. The nights would be cold, dark, and dangerous, forcing us to wait helplessly for the sun. All our food would be raw. No wonder we find comfort by a hearth.
BOOK: Catching Fire: How Cooking Made Us Human
9.82Mb size Format: txt, pdf, ePub
ads

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