Lecturer Examines Evolution 70,000 Years After Volcanic Eruption

Over two hundred attendees filled the Geological Lecture Hall at the Harvard Museum of Natural History Thursday evening to hear Professor Stanley H. Ambrose of  the University of Illinois at Urbana-Champaign illustrate the path of human evolution following a catastrophic volcanic eruption.

Ambrose was invited to speak by Christian A. Tryon, a Harvard professor of Anthropology. Tryon said Ambrose’s research is not only inspiring but also “hits all the buttons for the Harvard museums by bringing together anthropology, ecology, [and] environment.”

Prior to discussing its impact on humanity, Ambrose emphasized the magnitude of the eruption in question. When Mount Toba erupted approximately 74,000 years ago in what is now northern Sumatra, its ashes traveled to a distance equivalent to the width of the United States and covered more than 21 million square kilometers in a foot of ash, Ambrose said. The reflection of sunlight by the ashes triggered a six-year long volcanic winter that decimated life on Earth, including ancestral humans who lived in Africa.

Ambrose’s lecture focused on the competition for survival between humans and Neanderthals following the eruption of Mount Toba. He described Neanderthals as a violent and cannibalistic species that engaged in strenuous activities during the day.

After Toba, humans adapted to form cooperative social networks whereas Neanderthals failed to change, Ambrose said.

“With two people, or three people cooperating, they can feed the whole camp,” Ambrose said. “There’s no negative in reciprocity.”

Abandoning the “your gain is my loss” attitude unlike Neanderthals allowed humans to exchange information and explore unknown territories, eventually leading them to expand out of Africa to give rise to modern humans, he said.

Ambrose hypothesized that Neanderthals may have had a genetic predisposition for aggressive and uncooperative behavior that human ancestors lacked.

According to Jane Pickering, executive director of the Harvard Museums of Science and Culture, Ambrose’s lecture was one of many offered to the public by the various museums at Harvard.

—Staff writer Jessica Kim can be reached at jessica.kim@thecrimson.com.