No, I think it would be someone in Africa in either case. All non-Africans are more closely related to each other than to African populations.
So, it could be a bushman who is the most distant relation (unless the OP is a bushman). And don’t laugh. We have at least one poster here who has recent bushman ancestry.
With regard to the discussion of our most common recent ancestor: We seem to be basing this on Rohde, (lson & Change, Modelling the Recent Common Ancestry of All Living Humans, 431 Nature 562 (30 Sept 2004), links to the paper and related materials available at <html>http://www.stat.yale.edu/~jtc5/papers.html</html> (toward the bottom of the page). I don’t find their work terribly convincing. For example, they assume a migration rate across the Bering Strait of ten persons per generation, which I think far too high (although they argue that assuming just one person in each direction every ten generations - still too high, in my opinion - would push the date back only modestly). They also assume mixing between the Norse settlers of Greenland and the Inuit population, although those populations were perpetually at war and I know of no evidence for any admixture. There also is no discussion of the radically isolated Dani people of New Guinea, whose existence was unknown to the outside world until 1938. Because of peoples such as the Dani and native Hawaiians (there still are some pure-blooded Hawaiians with no European ancestry), and the likelihood that at least some native Americans have no European ancestry, you cannot just rely on post-Columbian developments.
Rohde et al. do acknowledge that Tasmanians in 1803 likely had no shared ancestors prior to 9000 - 12,000 years ago, but point out that there are no remaining native Tasmanians without some European or mainland Australian ancestry.
Their actual conclusion is more conservatively presented: that the date of the MRCA cannot be identified with great precision, but lived in the relatively recent past, “perhaps within the last few thousand years.” They also discuss the fact that, at some point a few thousand years before that, everyone with any surviving descendants at all is an ancestor to everyone alive today: “no matter the languages we speak or the colour of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who laboured to build the Great Pyramid of Khufu.” Actually, I’m pretty sure that not everyone alive today is descended from workers on the Great Pyramid, and it’s likely that we’re not all descended from Ukrainian horse domesticators, Chinese rice planters or American sloth hunters, but it’s still an interesting point.
The cited paper should be Rohde, Olson & Chang, not what I mistyped above.
John Mace: I don’t think that African populations were as radically isolated as those in some other parts of the world. Thus, you would expect to see a common ancestor between someone of European descent (as the OP apparently is) and pretty much any given African within, say, the last 2000 years or so.
That is the Identical Ancestor Point, thought to be between 5k and 15k years ago. So there’s a lot of wiggle room there.
Simply untrue. There are probably no “pure” Tasmanians left, that much is true.
Well genetics | Brad Ideas seems to show I was way out. The odds are that I’m related to someone at 16th cousin, and if you take it to 20th, the chances that we have no ancestors in common seem absurdly low. Formula he gives is:
My calculator won’t even give me an answer for something like 100th cousin!
That’s assuming that everyone on the planet mixes uniformly. It’s fine for a rough estimate, but a better model takes the geography into account.
I believe you mean Macassar. Their fortunes were made in the trepangle trade.