Final answer:
Jane Goodall discovered that chimpanzees make and use tools, a behavior previously thought unique to humans. Her work highlighted chimpanzees' cognitive abilities and significantly advanced our understanding of primate behavior and evolution.
Step-by-step explanation:
Primate expert Jane Goodall's major scientific discovery was the use of tools by chimpanzees. In 1960, she observed a chimpanzee adeptly using a twig to extract termites from their mound, thereby demonstrating tool-making capabilities among non-human primates. Prior to Goodall's work, the ability to make and use tools was considered a uniquely human trait.
Goodall's groundbreaking research extended beyond tool usage, also contributing significantly to our understanding of chimpanzee social structure, communication methods, and hunting behavior. Her observations opened new perspectives on primatology and human evolution, illustrating that primates shared cognitive abilities with humans. This revelation bridged a gap in understanding the evolutionary lineage and offered insights into the behavior and culture of our closest animal relatives.
Goodall's work also led to broader recognition of the intricate behavioral patterns of chimpanzees, highlighting their ability to adapt based on their environments. For example, chimps in Gombe National Park hunt without tools, while their counterparts in Fongoli use sharpened sticks as spears. All these behavioral studies underscore the complex intelligence of these animals and inform our interpretations of early human behavior.