Most people know Jane Goodall, who died Wednesday, as a silver-haired conservationist who chatted with Stephen Colbert and gave speeches to the United Nations in defense 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, Dr. 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 the 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.

Dr. 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.