These harsh conditions had both a physical and social influence on early human civilization. Humans were under the constant threat of attack from dangerous predators. As a result of this, early humans would always reside in groups. This allowed them to consistently be in a constant state of awareness for predators. It also gave them the advantage of being able to scare off dangerous threats as a group, should they be confronted. Rick Potts (2010) writes, many had warning calls as well; some were specific to attacks from birds, snakes, and leopards.
These conditions also affected how the bodies of early humans physically developed. Rick Potts writes (2010), as some early humans adapted to hot climates, they evolved narrow bodies that helped them stay cool. Long legs enabled them to travel longer distances. Eating meat and other foods that could be digested quickly led to a smaller digestive tract, making more energy available for tall bodies and large