How and why is Homo sapiens so successful?

By 30,000 years ago, Homo sapiens was the only type of hominin and had colonised most environments in the Old World. We argue that this success resulted from its ability to increase its population because more H. sapiens women than their contemporaries were able to have three or more children that survived into adulthood. This increased reproductive rate was accompanied by the development of a rounder brain and a longer childhood. A rounder brain and the accompanying re-organisation of the cerebellum and parietal areas increased our cognitive powers, and when combined with a longer childhood, allowed children to develop their imagination, ingenuity and inventiveness, all of which paid dividends when they became adults – in for example, being able to colonize new habitats or caring for infants and young mothers. Dietary factors may also have been important in ensuring that pregnant females and young children had an adequate diet, especially for women during their first and third trimester. In order to understand better our evolutionary success, we suggest a shift of focus from adult – and often largely male – activities such as big-game hunting towards the diet of infants and young mothers and the development rate of their children.