THE SCIENTIST WHO BROKE RULES

EXPERTS REFLECT ON THE LIFE OF JANE GOODALL WHOSE DISCOVERIES MADE US RETHINK WHAT IT MEANS TO BE HUMAN

- STORY: CARL ZIMMER AND EMILY ANTHES / NYT

Most people know Jane Goodall, who died on Wednesday at 91, as a silver-haired conservationist who chatted with Stephen Colbert and gave speeches to the United Nations in defence of nature. For scientists, however, it's the young Jane Goodall who followed wild chimpanzees for weeks at a time who endures as an icon.

"There will always only be one Jane Goodall," said Michael Tomasello, an expert on the origin of language at Duke University.

In 1957, Goodall's scientific career started with a phone call. At the time, she was only 23, having worked as a waitress and a secretary. But she had educated herself deeply about animals and wanted to find a way to work with them.

She called paleoanthropologist Louis Leakey, who at the time was uncovering spectacular fossils of early humans and apes in Africa. She impressed him so much that he offered to support an expedition to Tanzania, where she would observe chimpanzees.

Goodall began her work at Gombe Stream Research Center in 1960. The chimpanzees there grew accustomed to her presence, allowing her to learn how to tell them apart. Soon she began noticing them behaving in surprising ways.

She observed one male chimpanzee, whom she later named David Greybeard, deliberately break off a stalk of grass and slip it into a termite mound to fish for insects. Later, she saw other chimpanzees use tools as well.

When Goodall relayed her observations to Leakey, he was stunned. Making tools seemed like a hallmark of humans and far beyond the ability of a mere ape.

"Now we must redefine 'tool,' redefine 'man,' or accept chimpanzees as humans," he declared.

Goodall also uncovered a rich system of communication among Gombe's chimpanzees. The sounds they made were not random noises but distinct calls. They rounded out those calls with gestures made with their hands and heads.