For most of our evolutionary history, we did indeed live in Africa — but not just the eastern savannahs, as previously thought: our biological ancestors were distributed everywhere from Morocco to the Cape. Some of those populations remained isolated from each another for tens or even hundreds of thousand of years, cut off from their nearest relatives by deserts and rainforests. Strong regional traits developed. The result probably would have struck a modern observer as something more akin to a world inhabited by hobbits, giants and elves than anything we have direct experience of today, or in the more recent past.
Those elements that make up modern humans — the relatively uniform 'us' referred to above — seem only to have come together quite late in the process. In other words, if we think humans are different from each other now, it's largely illusory; and even such differences as do exist are utterly trivial and cosmetic, compared with what must have been happening in Africa during most of prehistory.
Let's not forget the Trolls!
The picture above features a reconstruction by Élisabeth Daynès.