Exploration and discovery are most likely a human and societal need, since curiosity is "built in" to humans, probably for evolutionary reasons. Those who were curious about the environment around them and beyond them were far more likely to survive and pass on their genes than those who were not. Exploration surely led to a greater awareness of dangers and a discovery of new places and things that were of great use. While individuals who were too curious and too risk-taking may not have survived, there must have been many who reaped the benefit of their explorations, nevertheless. So a society could expand its collective knowledge, even from the exploration and discovery of a few. As societies, for example, a tribe, grew larger, there was a need to expand territory, for the purpose of shelter and food, even if curiosity had not existed. Curiosity and the growing need for more food and shelter explain many of the early migrations of mankind from its origins, and it explains more recent phenomena such as the United States' westward expansion, the exploration of space, and our exploration of the earth's oceans. Yet another factor that explains exploration and discovery is what seems to be a human need for domination, which is probably another evolutionary mechanism that sometimes seems to be in overdrive, since it creates at least as many problems as it solves. So, this is a human and societal imperative that in many ways explains much of our individual and collective behavior.