An Introduction to Early Hominins and Baboons

Hominins are the evolutionary line that led to the genus Homo from the common ancestor shared with the genus Pan (chimpanzees and bonobos). Early hominins are loosely defined here as those that existed before about 1.7 million years ago, when major ecological and behavioral changes took place. Numerous genera and species of early hominins include Australopithecus and the earliest species of Homo. The term baboon in this book refers to monkeys of the genus Papio. These large primates can be divided into at least six species. Baboons are used to construct hypotheses about early hominins, based on analogous ecological conditions and comparable capabilities. Early hominins and baboons can both be characterized as medium-sized land mammals with significant sexual dimorphism in body mass. Both taxa adapted to a wide variety of habitats across much of Africa. Early hominins must have lived in complex societies and that is also true of all baboons. Differences between the hominins and baboons do not necessarily deter comparison. Baboons are quadrupedal and hominins bipedal, but both combined extensive time on the ground with climbing ability. Another important distinction is the canine teeth, large and dangerous in baboons, small in hominins. This does not impair comparison because early hominins were probably able to substitute hand-held weapons for large canine teeth.