When Did Humans First Appear on Earth?
There is evidence to suggest that archaic humans, of which modern humans are descended, were present as long as 195,000 years ago in what is now Ethiopia, as fossils recovered from the region show the beginnings of skull changes that evolved into the modern human skull. The first early human fossils were discovered in 1868 in southwest France.
All known fossil records suggest that the early humans that evolved into today's human beings were originally centered around the Ethiopia region initially, but began spreading into southern Africa, southwest Asia and Israel over the course of 70,000 - 100,000 years ago.
There are two theories concerning the evolution of modern humans: the replacement model and the regional continuity model.
The replacement model suggests that archaic humans evolved first in Africa, before spreading into the Old World where they replaced Neanderthals around 60,000 years ago. This would suggest that all humans share a common African ancestry.
The regional continuity model proposes that humans evolved at roughly the same time in different regions from various settlements of local archaic humans.
Both models agree, however, that modern man is certainly descended from the archaic African communities, although whether they are central to human evolution or merely a single part of it is still debated.