Geological deposits extending back two million years at Olduvai Gorge, Tanzania, provide well‐preserved fossil and archaeological evidence chronicling the biological and behavioral evolution of ancestral humans. Decades of research in the 20th century by Mary and Louis Leakey revealed key ancestral human fossils and archaeological sites of Early Pleistocene age, establishing the East African Rift Valley as the actual cradle of humankind and demonstrating the value of a team‐oriented approach in paleoanthropology.