It's been more than 40 years since I first set foot on the sandy beach of what is now Tanzania's Gombe National Park. The steep, heavily forested valleys and cascading streams on the shores of Lake Tanganyika formed the backdrop for one of the most thrilling phases of my life. Though I was armed with little more than secretarial training and a passion for animals, paleontologist Louis Leakey gave me a mandate:
Get the wild chimpanzees to accept you, observe their behaviors, and describe what you see. The rest, thanks in no small part to the National Geographic Society, is well-documented history.
We knew so little about these secretive creatures back then that everything seemed like a revelation. What were once thought to be peaceful, simple vegetarians turned out to be powerful, highly intelligent hunters with complex personalities and emotions: beings capable of communication, altruism, political alliances, infanticide, warfare, and tool making—the last once thought to distinguish humans from the rest of the animal kingdom.