The question then becomes, if the "out of Africa" hypothesis is an invalid one, then, from where or how did primitive humans emerge everywhere, it seems, to populate the globe, from one end to the other, in all sorts of climates and terrain?
After the "New World" was discovered by the "Old World," it was later surmised that the peoples of the Asian continent migrated eastwards across the Pacific and Bering Strait when ice levels were lower than now and they then further migrated throughout the Atlantic-Pacific continent, up, down, across, inside, from Coast to Coast, etc. And they migrated to Australia. And so on. And, various such theories and explanations of intentional or accidental migrations were given to account for the presence of primitive peoples just about everywhere. Further and further migration theories to explain anomalies and evidence. The explanations become more and more convoluted to me.
But, a different, more simple, direct explanation, hypothesis, supposition, an obvious one to me, exists that coincides better with the evidence. These people were THERE FROM THE BEGINNING. That is, the evolutionary antecedents of our modern human species populated the planet everywhere for millions of years and developed with different rates of change depending on accidental historical and geographical circumstances and isolation. Indeed, we can speculate, hypothesize that our evolutionary ancestors were distributed equally or unequally throughout the one large continent, Pangea, that existed prior to eventual continental drift and separation.
Just as Darwin noted species variations from place to place and, especially, on islands, we can postulate the same for human evolutionary precursors and development.
We can posit geographical pockets of human evolutionary existence with long and ancient continuity, comingled with relatively subsequent, modern, contemporary historical migrations and social overlap, interpenetration, integration, conquest, and so on.
If we begin with the above paradigm, assumption, theory, then, suddenly, questions and explanations shift dramatically.
That's the hypothesis. Now, it needs to be either proved or disproved.
So, I welcome comments from others...