Evolution Etc

http://www.alternet.org/story/139995/did_/?page=entire

"The long toes of H. floresiensis suggest they could be the direct descendants of a hominin similar to an early human ancestor such as H. habilis, rather than the more recent H. erectus, a species known to have migrated out of African long before the migration of our own species, H. sapiens."

Why do we have to go to this statement that, "We all came from Africa."? If we believe that all around the equatorial belt there was evolution happening at the same way, similar period of time. And the H. sapiens became more powerful so that they got rid of the other human species, like the H. floresiensis, like what is happening right now in all over the world. I heard recently that the Chinese come from a different branch of human species. I am not sure about this until I see the program on this coming Sunday in BBC.