In paleoanthropology, the hunting hypothesis is the hypothesis that human evolution was primarily influenced by the activity of hunting for relatively large and fast animals, and that the activity of hunting distinguished human ancestors from other hominids.
While it is undisputed that early humans were hunters, the importance of this fact for the final steps in the emergence of the Homo genus out of earlier australopithecines, with its bipedalism and production of stone tools (from about 2.5 million years ago), and eventually also control of fire (from about 1.5 million years ago), are emphasized in the “hunting hypothesis”, and de-emphasized in scenarios that stress the omnivore status of humans as their recipe for success, and social interaction, including mating behavior as essential in the emergence of language and culture.
Advocates of the hunting hypothesis tend to believe that tool use and toolmaking essential to effective hunting were an extremely important part of human evolution, and trace the origin of language and religion to a hunting context.
As societal evidence Buss (2011) cites that modern tribal societies use hunting as their primary means of acquiring food. The Aka pygmies in the Central African Republic spend 56% of their quest for nourishment hunting, 27% gathering, and 17% processing food. Additionally, the !Kung in Botswana retain 40% of their calories from hunting and this percentage varies from 20% to 90% depending on the season. For physical evidence Buss first looks to the guts of humans and apes. The human gut consists mainly of the small intestines, which are responsible for the rapid breakdown of proteins and absorption of nutrients. The ape’s gut is primarily colon, which indicates a vegetarian diet. This structural difference supports the hunting hypothesis in being an evolutionary branching point between modern humans and modern primates. Buss also cites human teeth in that fossilized human teeth have a thin enamel coating with very little heavy wear and tear that would result from a plant diet. The absence of thick enamel also indicates that historically humans have maintained a meat-heavy diet. Buss notes that the bones of animals human ancestors killed found at Olduvai Gorge have cut marks at strategic points on the bones that indicate tool usage and provide evidence for ancestral butchers.