Hominin evolution is the study of the biological and behavioral changes that have occurred in humans and their ancestors. This field of research explores the various species of the hominin lineage, from the earliest bipedal primates to modern Homo sapiens. Scientists study hominin fossils, genetics, and archaeological evidence to piece together the timeline of human evolution and understand the factors that have shaped the development of our species. Key topics in hominin evolution include the emergence of bipedalism, the evolution of larger brains, and the migration of hominins out of Africa.