You wouldn't know it by current world events, but humans actually evolved to be peaceful, cooperative and social animals.
In a new book, an anthropologist at Washington University in St. Louis goes against the prevailing view and argues that primates, including early humans, evolved not as hunters but as prey of many predators, including wild dogs and cats, hyenas, eagles and crocodiles.
Despite popular theories posed in research papers and popular literature, early man was not an aggressive killer, argues Robert W. Sussman, Ph.D., professor of anthropology in Arts & Sciences.
Sussman's book, "Man the Hunted: Primates, Predators and Human Evolution," poses a new theory, based on the fossil record and living primate species, that primates have been prey for millions of years, a fact that greatly influenced the evolution of early man.
Our intelligence, cooperation and many other features we have as modern humans developed from our attempts to out-smart the predator, says Sussman.
Since the 1924 discovery of the first early humans, australopithicenes, which lived from seven million years ago to two million years ago, many scientists theorized that those early human ancestors were hunters and possessed a killer instinct.
Through his research and writing, Sussman has worked for years to debunk that theory. An expert in the ecology and social structure of primates, Sussman does extensive fieldwork in primate behavior and ecology in Costa Rica, Guyana, Madagascar and Mauritius. He is the author and editor of several books, including "The Origins and Nature of Sociality," "Primate Ecology and Social Structure," and "The Biological Basis of Human Behavior: A Critical Review."
The idea of "Man the Hunter" is the generally accepted paradigm of human evolution, says Sussman, who recently served as editor of American Anthropologist. "It developed from a basic Judeo-Christian ideology of man being inherently evil, aggressive and a natural killer. In fact, when you really examine the fossil and living non-human primate evidence, that is just not the case."
Studying the fossil evidence
And examine the evidence they did. Sussman and Hart's research is based on studying the fossil evidence dating back nearly seven million years. "Most theories on Man the Hunter fail to incorporate this key fossil evidence," Sussman says. "We wanted evidence, not just theory. We thoroughly examined literature available on the skulls, bones, footprints and on environmental evidence, both of our hominid ancestors and the predators that coexisted with them."
Since the process of human evolution is so long and varied, Sussman and Hart decided to focus their research on one specific species, Australopithecus afarensis, which lived between five million and two and a half million years ago and is one of the better known early human species. Most paleontologists agree that Australopithecus afarensis is the common link between fossils that came before and those that came after. It shares dental, cranial and skeletal traits with both. It's also a very well-represented species in the fossil record.
"Australopithecus afarensis was probably quite strong, like a small ape," Sussman says. Adults ranged from around 3 to 5 feet and they weighed 60-100 pounds. They were basically smallish bipedal primates. Their teeth were relatively small, very much like modern humans, and they were fruit and nut eaters.
But what Sussman and Hart discovered is that Australopithecus afarensis was not dentally pre-adapted to eat meat. "It didn't have the sharp shearing blades necessary to retain and cut such foods," Sussman says. "These early humans simply couldn't eat meat. If they couldn't eat meat, why would they hunt?"