Human Evolution

The story of human evolution began in Africa about six million years ago and it describes the very long process that our ancestors went through to ultimately become modern humans. This process has been uncovered by studying fossils and understanding the underlying theory of evolution, and while new fossils are uncovered every decade revealing new chapters, scientists agree about the basic story.
Evolution means the changes that occur in a population over time. 
evolution is a process that results in changes that are passed on or inherited from generation to generation. It does not, for example, describe how people can change their muscle mass by lifting weights.
Some individuals inherit characteristics that make them more successful at surviving and having babies...
   Biological evolution explains the way all living things evolved over billions of years from a single common ancestor. This concept is often illustrated by the so-called tree of life. Every branch on the tree represents a species. The fork separating one species from another represents the common ancestor that each pair of species shared. So ultimately, all life is interconnected, but any two species may be separated by millions or even billions of years of evolution.

Our Common Ancestor

Most scientists believe our common ancestor existed 5 to 8 million years ago. Then two species broke off into separate lineages, one ultimately evolving into gorillas and chimps, the other evolving into early humans called hominids. In the millions of years that followed, at least a dozen different species of human like creatures have existed, reflected in the fossil discoveries of paleoanthropologists, although many of these species are close relatives but not actual ancestors of modern humans.