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Comment by hollerith | Hacker News Reader

Most sub-Saharan Africans have no Asian ancestors -- or at least that is our best guess. (Conversely, everyone has ancestors who lived in sub-Saharan Africa.)

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I don’t think it works like that. Gene mixing happens all over the world and our nearest common ancestor of everyone alive today is only 3000 years ago.

http://www.stat.yale.edu/~jtc5/papers/CommonAncestors/Nature...

> ignored such complexities as geography and migration

That article doesn't look compelling when refuting a claim that depends entirely on geography and migration.

Not that I'm particularly convinced myself but you quoted the part about the prior paper, not the one the link was talking about:

> The current paper presents more realistic mathematical and computer models. It incorporates factors such as socially driven mating, physical barriers of geography and migration, and recorded historical events.

That's embarrassing. Thank you.

There is zero chance our nearest common ancestor was only 3000 years ago.

Feel free to post scientific papers that show this.

A moment's logical thinking demonstrates it. "Scientific papers" are not the currency of correctness.

And yet they are worth infinitely more than simple contradiction free of any evidence whatsoever.

A moment's though yet you can't write it down?

I wonder if the authors of the paper thought about that issue. How is "nearest common ancestor" defined?

The paper uses the proper term "most recent common ancestor" (commonly abbreviated MRCA) which specifically means the most recent individual from which all individuals of a set (such as "all humans") are genetically descended from (i.e. if you traced everyone's lineage at least one branch up the tree would always hit this person, not that this person was the only source of genetic information from that time).

Clarity: it should have read "if you traced everyone's lineage _then_ at least one branch _somewhere_ up the tree would...".

I realized the way it was written could be ambiguously read as "if you traced everyone's lineage _by_ one branch up" after the edit window had passed.

> Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and migration. Those precise mathematical results showed that in a world obeying the simplified assumptions, the most recent common ancestor would have lived less than 1,000 years ago. He also introduced the "identical ancestors point," the most recent time -- less than 2,000 years ago in the simplified model -- when each person was an ancestor to all or ancestor to none of the people alive today

This is clearly ridiculous. We have historical written records to know this isn’t true.

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