Did Climate Change Drive Human Evolution?
There's a plan afoot among evolutionary scientists to launch a big new project — to look back in time and find out how climate change over millions of years affected human evolution.
A panel of experts from the National Academy of Sciences in Washington, D.C., has given its blessing to the plan. They say it could unveil a whole new side of human history.
Anthropologist Rick Potts, who heads the human origins department at the Smithsonian Museum of Natural History, has been pushing the idea that "climate made us" for years.
Lately, he's been putting together an exhibit called "What Does It Mean to Be Human?" Among cabinets displaying dozens of skulls of human ancestors, and bronze statues of Neanderthals and other evolutionary experiments, there are displays suggesting the novel idea that climate change influenced how we evolved.
"The explanations that we've had tied human origins back to an African savannah or to a European ice age," Potts says, "and it was never really adequate to understand the plasticity, the versatility of the human species."
Habitats Kept Changing, And So Did The Humans
Darwin's idea was that living things adapt to a place — a habitat.
But Potts says habitats kept changing because climates kept changing. Centuries of drought, for example, would shift to centuries of monsoons, over and over. Which raises a question, Potts says: "Not how did humans become adapted to a specific ancestral environment, but how did we become adaptable?" Extraordinarily adaptable to so many different environments.
"And that's a totally new question," he says, "one that Darwin never really addressed."
Potts is one of the authors of the National Academy of Sciences report, and proposes that it was flip-flopping climate that sparked some of our biggest evolutionary adaptations — the invention of better tools, for example, or a bigger brain.
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