I see also many human remains in Europe and Asia..Sinanthropus Pekinensis and others..
Yes, there are remains in Europe and Asia. Because the first humans evolved in Africa (the oldest remains) and THEN spread to Europe, Asia, and eventually the Americans. Thats why the remains found there are significantly younger.
Yes, but all of the oldest remains are found in Africa and it is demonstrable that all of the subspecies of humans found in other parts of the world are descended from the original hominids who evolved in Africa.
No, it's not silly. You ignore TIME as a variable. We carry within us the history of Human Origins. Our DNA, and the variation we see within it in the world, shows us humans evolved in Africa over 200,000 years ago, and moved out of Africa at least 60,000 years ago.