Now its like an alien came to earth and saw what a mess early human's were and figured he could do something to improve they're chances so that they might win later on. He creates variations on humans, and makes them find out some of his secrets and then poof vanishes. Human's then find they are vulnerable to predators and spend part of their lives in caves. This is no romantic period because we were very nasty and would kill each other in a fit of rage. But we persisted. Other species came and went, and still we stood.