IIRC from Wells' work the entire population of homo sapiens was about 2,000 individuals in West Africa about 70,000 years ago.
"Why do researchers believe that we, modern humans, originate from Africa?
Initially there were two suggestions about where modern humans come from. The 1st suggestion is that human ancestors dispersed throughout the globe, and modern humans evolved from this predecessor in various locations around the globe. The 2nd one is that all modern humans have the same ancestors, who emigrated from Africa some 60,000 years ago. After all data are analyzed, the latest suggestion appears to have advantage over the 1st one based on the following results:
1.Researchers have found fossils of modern humans in Africa, Australia, Europe, Asia, and America. From analyzing fossils, they conclude that fossils in Africa were older than the ones in other continents.
2.MtDNA testing had been done on some people alive around the world in 1987, and the result concluded that humans had mtDNA coming from the same woman who lived some 200,000 years ago in Africa. The fossils testing did confirm the finding that there were modern human fossils at that time frame in Africa. This means that woman was our great, great, great, great, great,,,,, grand mother. Scientists named her "Eve" or "Mitochondrial Eve". Note that Eve here is not Eve in the christian bible.
3.Y chromosome - according to National Geographic researchers team, all living men have common male ancestor, who lived some 60,000 years ago. They named him "Adam", and thus he is the great, great, great, great, great,,,,,,, grand father of all men alive today.
4.The current DNA testing (last year) on people alive today did confirm that we are all originated from Africa."
sorchek.org
