Modern Humans from Upper Botswana, Article

Several days ago CNN came out with an article that states that the descendants of modern humans came from Upper Botswana. It goes on to say that the first modern humans lived in a type of wet lands within the region and grew to great numbers over time.
Link to article to read more:

Here’s an interesting reply:

From the article:

“I’m persuaded that southern Africa was an important area for human evolution,” says population geneticist Aylwyn Scally of the University of Cambridge in the United Kingdom who was not involved with the work. But, he says, studies of living people’s DNA can’t reveal the precise location of our ancestors. “It would be astonishing if all our genetic ancestry at this time arose in one small homeland.”

But mtDNA alone in living people is a poor tool for tracking ancient population history in Africa, says evolutionary geneticist Sarah Tishkoff of the University of Pennsylvania. MtDNA traces only one genetic lineage passed from mothers to their children over time. If the researchers had traced the evolution of Y chromosomes inherited from fathers or of any nuclear genes inherited from both parents, they might have gotten many different answers, Scally adds.

Hayes responds that the team chose mtDNA because it doesn’t get shuffled in early fetal development like other types of DNA do. As a result, it can be used to trace living people’s evolution in a direct line to a small number of female ancestors who only lived in southern Africa, she says. “It acts like a time capsule for our ancestral mothers.”

The research article in Nature: