Some 10,000 years ago, a massive shift occurred in how humans obtained food. Rather than hunting and gathering, they domesticated animals and plants. This changed not only how humans ate, but also their societal structure, health and mentality, said Spencer Wells, an explorer-in-residence at the National Geographic Society, in his first visit to campus as a Frank H.T. Rhodes Class of '56 Professor.
Wells, a population geneticist and anthropologist, spoke to a near-full audience in Call Auditorium March 2 about the genesis and effects of this "neolithic revolution" and its influence on current society, themes that will be spelled out in Wells' upcoming book, "Pandora's Seed: The Unforeseen Cost of Civilization."
Wells, director of the Genographic Project of the National Geographic Society, spent the week on campus staying at Carl Becker House on West Campus; he also spoke to several biology classes at Cornell and Ithaca College, presented several seminars on West Campus and met with faculty and students from across campus in fields from biology and anthropology to theater, film and dance and the social sciences.
He focused his March 2 talk on the genetic, geologic and archaeological evidence for the dawn of plant and animal domestication. He said that geological and archaeological evidence suggests that agriculture emerged shortly after the end of the Pleistocene Epoch. As the glaciers retreated, humans developed villages in the new, plentiful landscape, he said. Shortly after the Pleistocene, a smaller ice age termed "the Younger Dryas" occurred, causing a food crisis. To survive in the dwindling number of non-glaciated areas, they developed agriculture.
Agriculture, he said, profoundly affected the diet, health and societal structure of humans. While hunter-gatherers ate about 150 species of plants, once corn was domesticated, 75 percent of North Americans' diet was corn based within a few hundred years.
"What used to be [hunting-related] threats from without were now threats from within," Wells said, referring to the transition from hunting-related, trauma-induced deaths in hunter-gatherer society to deaths due to infection and poor diet in neolithic and modern society.
The change in diet also affected the mentality of ancient people, he said. People in hunter-gatherer societies told stories of their ancestors and had time to be creative at the end of the day. This free time was slowly eroded during the age of domestication, he said, and now we're experiencing an "age of anxiety." Wells speculated that the increasing number of people taking antidepressants may be a consequence of the shrinking free time over the past few thousand years. "For the first time in history, people have to take drugs to be normal," he said.
As for the future, one in which the world population nears 10 billion and food shortages may be likely and the planet is dangerously warming, Wells said humans needed to be less materialistic. He added, "Saving ourselves will mean accepting human nature, not suppressing it ... it will mean learning from people who retain a link back to the way we lived for virtually our entire evolutionary history."
Haley Hunter-Zinc, a graduate student in computational biology, said she was struck by Wells' ability to merge archaeology and ethics with genetics. "He definitely raises a lot of questions that a lot of us are thinking about," she said.
Wells' appointment as a Rhodes professor extends to 2012. His visit was also sponsored by the Cornell Center for Comparative and Population Genomics.
Graduate student Kate Neafsey is writer intern for the Cornell Chronicle.