As I understood it Africans populated Africa, followed the coast of the Indian Ocean and populated it all the way down to Australia and its surrounding islands, and were pretty much left alone. Somewhere in the Middle East the Arabs formed. They took over the Northern Africa and Saudi Arabic island, moved down to India and settled there aswell. From somewhere that I don't know the Asians spawned. Took over all of Eastern Asia and eastern Russia, migrated to America and became Native American. The Arabs migrated to Europe and became white people, and settled in all of Europe.

This is what I think happened with my basic understanding of history. This would explain most ethnicities and why say aboriginals looked more like Africans and not Asian like its northern neighbors.

I am not at all sure with the time periods of these happenings and I would like to get some sources and corrections of my understanding, and also time periods. Thank you so much in before hand!

EDIT I'm sorry if I am super wrong and this is a bad question. I'm just really interested in the subject and want to get a good image of how and where we settled the whole earth! Thanks again for any answers!

Also sorry if I'm offending anyone with my use of ethnicity as if we were different species. English is also not my first language so my phrasing might be off