Apes That Walked Upright (About Three Million Years Ago)

Abstract

Your ancestors who lived three million years ago were still good at climbing trees, but they no longer spent most of their time in the forest. Their bodies were adapted to walking around on the ground and eating tougher food. They foraged in drier environments where food and sources of water were further apart, and they were more exposed to predators. This environment was particularly difficult for mothers and infants, but they could cope if they grouped together and helped each other. They could take turns being foragers and bringing back food and being babysitters, looking after their young ones in a defendable place with water nearby. This provided a different social environment than that of apes that stayed in the forest. Youngsters had to be quieter and less aggressive. And they were able to learn by watching several different adults and older children, observing different foraging techniques. There was more to learn, and natural selection would have favored the individuals who chose to learn more effective techniques.