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A breakthrough theory that tools and technology are the real drivers of human evolution
Although humans are one of the great apes, along with chimpanzees, gorillas, and orangutans, we are remarkably different from them. Unlike our cousins who subsist on raw food, spend their days and nights outdoors, and wear a thick coat of hair, humans are entirely dependent on artificial things, such as clothing, shelter, and the use of tools, and would die in nature without them. Yet, despite our status as the weakest ape, we are the masters of this planet. Given these inherent deficits, how did humans come out on top?
In this fascinating new account of our origins, leading archaeologist Timothy Taylor proposes a new way of thinking about human evolution through our relationship with objects. Drawing on the latest fossil evidence, Taylor argues that at each step of our species' development, humans made choices that caused us to assume greater control of our evolution. Our appropriation of objects allowed us to walk upright, lose our body hair, and grow significantly larger brains. As we push the frontiers of scientific technology, creating prosthetics, intelligent implants, and artificially modified genes, we continue a process that started in the prehistoric past, when we first began to extend our powers through objects.
Weaving together lively discussions of major discoveries of human skeletons and artifacts with a reexamination of Darwin's theory of evolution, Taylor takes us on an exciting and challenging journey that begins to answer the fundamental question about our existence: what makes humans unique, and what does that mean for our future?
About the Author
Timothy Taylor, PhD is the author of The Buried Soul and The Prehistory of Sex. He has appeared on the History Channel, the Discovery Channel, and National Geographic specials. He contributes to such publications as Nature, Scientific American, and World Archaeology, and is editor-in-chief of the Journal of World Prehistory. He teaches archaeology at the University of Bradford in the United Kingdom.
Read an Excerpt
The Artificial Ape
How Technology Changed the Course of Human Evolution
By Timothy Taylor
Palgrave MacmillanCopyright © 2010 Timothy Taylor
All rights reserved.
SURVIVAL OF THE WEAKEST
A fox (canis fulvipes), of a kind said to be peculiar to the island, and very rare in it, and which is a new species, was sitting on the rocks. He was so intently absorbed in watching the work of the officers, that I was able, by quietly walking up behind, to knock him on the head with my geological hammer.
—Charles Darwin, Journal of Researches, December 6, 1834
IN THE HIGH ALPS a 5,000-year-old frozen corpse, "Ötzi the Ice Man," lay beside his longbow. The axe marks had not been smoothed off, but the functional aspects were complete—it was a replacement weapon, made in haste. We know he was a man in a hurry: sophisticated forensic archaeological analysis has revealed his story, from the sequence of inhaled tree pollens in his lungs, characteristic of different altitudes, to his stomach contents and the scans that show a rib broken only days before death. He had, my Austrian colleagues are now convinced, been on the run, up mountains and down valleys, for several days, living rough, pursued, desperate to rearm himself, and finally driven toward a high mountain pass with a blizzard threatening. There he was shot in the back from a distance by an expert. Still running, he reached back to grasp the shaft where it projected beneath his shoulder blade; it snapped, leaving the flint arrowhead lodged. The internal bleeding was unstoppable, and by now out of sight of his enemies, he collapsed into the first heavy snow of winter and died. Ice closed over him, and he vanished from memory until 1991, when global warming, acting on the Ötztal glacier, melted him back into view. By the time of Ötzi's death, in the later Neolithic period around 3300 B.C., human beings had long been the planet's top predator, fearing mostly each other.
Before Ötzi died, he had been a farmer who, from time to time, also hunted. He was part of a wave of colonization and economic change that had been sweeping into central Europe from the Balkans (and ultimately western Asia) since 5500 B.C. His ancestors had carved out territory in a zone previously dominated by dedicated wilderness dwellers. These were people who had never had domestic animals or fenced off land. They were mobile and innovative bands of men, women, and children who hunted, fished, and gathered. Their communities had expanded rapidly into the burgeoning new forests of Europe around 10,000 years ago, after the ice sheets receded and the climate quickly warmed. These Mesolithic people were in turn descended from big-game hunters whose lineage can be traced back to a time when mammoth-hunting scenes were painted on cave walls.
This period, the Upper Paleolithic, was when the previous lords of Europe, the Neanderthals, were being squeezed out by our kind, anatomically modern Homo sapiens, first arriving from the Near East around 40,000 years ago. Neanderthals had weathered successive periods of advancing and retreating ice over the previous quarter of a million years. Before them had been Homo heidelbergensis, and, yet further back, Homo erectus. The sequence of kinds of humans, and kinds of human culture, arriving in waves over the hundreds of millennia before Ötzi's death is at least as complex as the history of Europe since that date. To understand how Ötzi (and we) came to look physically modern, to be able to think intelligently and make use of tools and weapons, we will have to track back far earlier, to a point even before there were humans.
* * *
I am unconvinced by the current understanding of our evolution— not whether or when evolutionary changes took place, but how and why. Like my academic colleagues, I have no doubt that humans emerged over vast spans of time, that our distant ancestors were apes, and that we are biological creatures. The results of each new field season of research in paleoanthropology—a new pelvis from Ethiopia, a different sort of small-headed Homo erectus from the high Caucasus Mountains, a new, very early tree-living ape that might be placed on or off our direct ancestral line according to highly technical arguments and scholarly taste—important as they are, do not change the basic fact that humans evolved from apes.
This simple fact is often misunderstood: "If we evolved from chimpanzees, then why are there still chimpanzees?" asked one child, after an introductory lecture I had given his school class, sure that he had spotted the killer weakness in the evolution argument. The answer, of course, is that we didn't. Chimpanzees have evolved alongside us since a point, maybe 7 million years ago, when we formed a single breeding community of some kind of ape. That ape, whatever it was, was much more like a chimpanzee than like us, and that means that modern chimpanzees have not evolved as dramatically as we have. One group of apes continued doing what they had been doing pretty successfully. They may have moved down from trees more, and evolved knuckle-walking, but they never walked fully upright. They kept their insulating fur, never finding a need for clothes, never freeing up their hands to make them, or developing brains large enough to think of them. The other group, split off perhaps by a simple fact of geography, got embroiled in something else. What happened to them was very different and very varied: before we emerged as the only surviving upright-walking ape, there were numerous prototypes, most of them evolutionary dead ends.
Darwin had no access to the African fossil record—he suspected it might exist, but he did not live long enough to see even the first finds. But he did apply some smart thinking to the living species of ape he knew about. He considered it significant that two kinds of great ape— gorillas and chimpanzees (two species of each are now recognized)— lived in the wild in Africa while only one—the orangutan (also now divided into two species)—lived wild outside it, in southeast Asia. Using the same logic he had applied to the evolution of birds and fish, Darwin argued that Africa, as home to the most kinds of great ape, should be the continent on which the common ancestor of apes and humans had lived. He predicted, in advance of the fossil evidence, that it would be there that any intermediate "missing links" would be discovered.
Darwin upheld his African origin theory even after the discovery of the first Neanderthal skeleton in Germany, believing (correctly, as it turns out) that Neanderthals were relatively modern, being a parallel line of later human evolution and not an intermediate link with apes. It was nearly a decade after Darwin's death that the first physical evidence for a missing link came to light, at Trinil in Java. Although "Java Man," now classified as Homo erectus, was, like the orangutan, also outside Africa, paleontological fieldwork throughout the twentieth century and up to the present shows that the most significant phases of human evolution happened in Africa.
Discoveries from the African Rift Valley, down into southern Africa and across to northern Africa—everywhere that conditions have been conducive to the fossilized preservation of ancient bone—follow so thick and fast that it is hard to publish a detailed scheme of human evolution without its being immediately out of date. The evolutionary tree (or bush) of human and humanlike evolution is continually added to and reformatted, with all the controversy that entails. Several plausible versions exist at any one time as scholars connect the dots between a bewildering number of different upright-walking ape species that existed, often in parallel, between 5 and 1 million years ago. Upright-walking apes are collectively known as hominins; in the light of genetic studies, the older and more familiar term, hominid, has been extended to include chimpanzees, gorillas, and orangutans. All of this—the analysis and reanalysis, the dot-joining, and the terminological evolution—is science, and the myth-bound creationists who claim that the revisions, occasional mistakes, and even the rare misrepresentations of paleoanthropologists and archaeologists betray uncertainty about whether evolution happened fail to comprehend that evidence-based research, at its best, has no dogma.
Every year, new discoveries add complexity to the several million years' worth of explosive changes that differentiate our species from hairy, knuckle-walking, inarticulate apes. Chimpanzee, gorilla, and orangutan intelligence has been maligned in the past; their potential for communication using sounds and tokens, along with their tool-using abilities and level of social complexity, was previously underrated; and respectable estimates of genetic closeness put them within 5 percent of "being human." But this book is not about how like us they are, but the mystery of how different we have managed to become, and continue to become. Biological logic alone cannot explain it.
Biological evolution is both fact and theory. Fact in the way that the earth's roundness is fact: our world may look and feel flat, but we can sail or fly across it without changing direction and get back to where we started. Equally, we can now watch biological evolution in the lab as new strains of virus and bacterium develop, at times too rapidly for adequate medical response. This is something we are desperateto understand better, and our struggle gives birth to theory, which is tested and refined. In the same way, theory supplies scenarios for the condensation of stars and the birth of solar systems like ours, in which spherical planets can form. The best current theory for the creation of sphericality remains uncertain and incomplete (gravity is involved, and we do not completely understand that yet). The condensation of our planet only happened once, so we cannot go back and check it. But that does not make the world flat: we cannot sail off the edge of the ocean into some medieval vision of Hell.
Even so, the ability to view our blue planet floating as a globe in space has brought home the reality; and human evolution, while no less real, has no such indisputable graphic proof. Nevertheless, the basic facts are clear: we descended from apes, lost our fur, began to walk upright, trebled or quadrupled our brain capacity, and created a culture that includes tools, language, ideas, and values, ultimately becoming smart enough to look back over this process and analyze it.
* * *
Ötzi, like us and like his earlier prehistoric ancestors, did not face the world naked. He had elaborate gear—for protection, for making, for killing. When he took his bow into the forest to hunt deer, he did not do what all other predators do—lurk, chase, and harry until an old, weak animal is brought to bay, or a young fawn is separated from its mother. Ötzi would have left the old and weak for lesser predators like wolf and lynx, and would have started the fawn in the right direction to rejoin its family. Ötzi had an interest in managing the wild. He was after the biggest and best—it would provide the most meat, and the most status when its antlers were placed above his cabin door.
Because he had a bow, Ötzi undermined the logic of evolution. In the old biological arms race, predators who were too slow starved, and the fastest prey escaped, with the result that the fittest in each species survived to pass on its genes. But the idea of individual fitness driving evolution is an approximation. More precisely, every species has an "inclusive fitness" that represents the sum total reproductive effectiveness of its genes in a particular environment. Some extremely fit animals may sacrifice themselves to protect close kin, or so that the broader group lives on in good numbers, preserving a better complement of the species' "best" genes. Species also tweak each other's inclusive fitness. In North America, wolves, by hunting elk (moose), increase their prey's inclusive fitness by removing the old and diseased from the breeding pool. And just by chasing their prey around, wolf packs limit the time the elk can stay in large herds in one place—conditions under which diseases would otherwise easily become endemic. The wolves keep the elk fit, and vice versa: wolf packs with lower average stamina or less social cohesion will do less well, catching fewer elk and producing fewer offspring to reproduce themselves.
Once humans emerge, this biological arms race is replaced by a more familiar (and real) one. Tools and weapons have been called the "extra-somatic means of adaptation for the human organism," enhancing innate somatic (or body) strength beyond what would seem naturally possible (this complex of artifacts and technological know-how that belong to my System 3).The unprecedented power of a longbow like Ötzi's allows even a hunter with a serious physical disadvantage (bad legs, say) to ambush and bring down the fittest beast in a herd. Through technology, the laws of nature are supplanted by the will of humans.
Darwin's little fox, living quietly on an island off the coast of Chile, had no response to the hammer that the great naturalist wielded, and ended up, stuffed, in the collection of the Royal Zoological Society in London. But the real weapon was not the hammer but the ship, the Beagle—a floating support system that allowed a contingent of our species to arrive unannounced almost anywhere in the world. During the Beagle's voyage the body count rose swiftly. The crew killed to eat—as much from curiosity as hunger (Darwin ate a puma in Patagonia)—and sometimes to drink (as when Darwin slashed open the bladder of a live Australian land tortoise during a desert crossing). They also killed to protect themselves, but principally they killed to provide the basis for the most important zoological study of all time. The voyage of the Beagle led to the development of the magnificent theory of evolution by natural selection, and the idea of the survival of the fittest. So it is ironic that the specimens themselves were selected artificially, with the weak, small, and ill rejected in favor of those that, until their untimely deaths, had been in peak condition.
Darwin's ideas dominated intellectual conversation in late Victorian Britain. While the novelist George Eliot wrote in one of her letters, "Natural selection is not always good and depends (see Darwin) on many caprices of very foolish animals," capturing very honestly the bleak logic of natural selection, others wanted a teleological explanation. That is, they wanted nature to have an aim. If it could no longer be God-given beauty, at least it could be fitness—an idea of perfect adaptation to a given environment. The phrase "survival of the fittest" was coined not by Darwin but by a follower with a more social and political agenda, Herbert Spencer. Nevertheless, Darwin was persuaded to adopt the phrase after the fourth printing of The Origin of Species by Means of Natural Selection. As an enthusiastic hunter, he must have been keenly aware that, while the slowest antelope would be eaten by the cheetah, an antelope fit enough to outrun a cheetah was thereby a prize trophy, potentially bringing praise, status, and perhaps even enhanced access to reproduction for its human killer. So which would be the "fitter"?
One fitness ploy for antelopes might be to develop superb camouflage, outwitting both cheetahs and humans. But such coloration might look so dull that the antelope would not find a mate. Darwin recognized that animals had, at times, to strut their stuff, whatever the risk. Without an overarching, single-strand idea of fitness, analyzing the pressures that caused species to evolve was very challenging, and Darwin developed his theory of sexual selection to take care of part of the problem. The classic exposition of sexual selection relates to the peacock's tail (and has become infamous because of the way Darwin extrapolated from it to explain why—in his opinion—his wife, Emma Wedgwood, was less smart than he was).
The clash between different kinds of fitness, and between the mechanisms of natural selection (external to a species as it battles for survival) and sexual selection (internal to a species as its members consider potential mates), puts tension into biological systems. That this creates unpredictable results is well known. Nor is the directed interference of humans in the evolutionary paths of other animals unfamiliar. Most environmental scientists, genetic engineers, and evolutionary biologists agree that nature is increasingly under the direct control of science and technology. We have seized the reins of evolution, and even if we cannot direct it with full confidence, we are changing its course. Genetic engineering is the obvious modern example, but if we look at all the domesticated farm animals and pets around us, it becomes clear that our active interference has a long history. The natural equations of wild survival are in recession: in future, we alone will define fitness.
Although the power of technology today is unprecedented, the tipping point occurred over 2.5 million years ago. The dawn of the technological era is signaled archaeologically by the first chipped stone artifact—a tool or weapon plausibly used for killing big game. After that point, for animals confronted by humans, the characteristics that would ordinarily convey fitness could increasingly become a liability. The process of natural selection and survival of the fittest was undermined. Intelligent humans with weapons could kill whichever animals they liked, fit or unfit, young or old, large or small, and the animals, trapped by the biology of inheritance, had no effective response.
Excerpted from The Artificial Ape by Timothy Taylor. Copyright © 2010 Timothy Taylor. Excerpted by permission of Palgrave Macmillan.
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Table of Contents
Survival of the Weakest
Walking and Chewing Gum
The Brno Effect
Men in White Coats
De-evolution and Counterbiology
Sailing in Tradescant's Ark
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