Answer:Humans began to evolve about seven million years ago, and progressed through four stages of evolution. Research shows that the first modern humans appeared 200,000 years ago.
Neanderthals were a separate species from humans. Although they had larger brain capacity and interbred with humans, they eventually died out.
A number of theories examine the relationship between environmental conditions and human evolution.
The main human adaptations have included bipedalism, larger brain size, and reduced sexual dimorphism.
