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Johannes de León
Wednesday, October 6th, 2004, 08:52 PM
In this week's issue of Nature (http://www.nature.com/), a Yale mathematician presents models showing that the most recent person who was a direct ancestor of all humans currently alive may have lived just a few thousand years ago. "While we may not all be 'brothers,' the models suggest we are all hundredth cousins or so," said Joseph T. Chang (http://www.stat.yale.edu/people/josephchang.html), professor in the Department of Statistics (http://www.stat.yale.edu/) at Yale University (http://www.yale.edu/) and senior author on the paper.

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.

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. Although such complexities make pure mathematical analysis difficult, it was possible to integrate them into an elaborate computer simulation model. The computer repeatedly simulated history under varying assumptions, tracking the lives, movements, and reproduction of all people who lived within the last 20,000 years.

These more realistic models estimate that the most recent common ancestor of mankind lived as recently as about 3,000 years ago, and the identical ancestors point was as recent as several thousand years ago. The paper suggests, "No matter the languages we speak or the color 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 labored to build the Great Pyramid of Khufu."

The results can also work backwards, into the future. According to Chang, "Within two thousand years, it is likely that everyone on earth will be descended from most of us."




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Other authors are Douglas L.T. Rhode of the Massachusetts Institute of Technology and Steve Olson of Bethesda, MD. The National Institutes of Health supported this research.

Citation: Nature 431: (September 30, 2004). For solicited commentary on this paper, see News & Views and supplementary material in the same issue.


[Source (http://www.eurekalert.org/pub_releases/2004-09/yu-rc092904.php)]

AryanKrieger
Wednesday, October 6th, 2004, 09:17 PM
With respect, the man is a mathematician not a scientist and genetics does not recognise such a recent common ancestor. One suspects that there is another agenda behind his dubious assumptions.

As an Aryan I have absolutely nothing in common with ape like races who inhabit Africa. No genetics can establish any such common link within just a few thousand years.

Tricknologist
Sunday, October 24th, 2004, 12:36 AM
Proffesor Chang needs to read Carelton Coons "Origin of Races". Coon makes a pretty good case that the races had seperated at the pre-sapien stage.

But then again, coming from an American ivy league university, Chang is probably just doing a politically motivated hack job.

Triglav
Sunday, October 24th, 2004, 01:05 AM
The "old man" of Cro-Magnon is 24,000 old and the oldest European is 35,000 years (http://dsc.discovery.com/news/afp/20030922/jawfossil.html) old. What is the purpose of this study?

nordic_canadian_male
Thursday, November 4th, 2004, 08:14 PM
stupid chink, so we have written records dating before our common ancestors lol. He should really review his study, this is the most rediculous shit i've ever heard. This whole movement of trying to unite mankind through fake science has to end, the mitrachodrial DNA thing was already too much, now this.

Narcissus
Friday, November 5th, 2004, 01:11 AM
I had forgotten what a bastion of flat-earthers Skadi was, thanks for reminding me, posters.

I've seen this study before, and as an amateur genealogist, I'd say it's far more than plausible.

Nordic Canadian Male, you've completely misunderstood the study (though you're not the only one). It's not saying that the proverbial "Adam" from who all humans sprung was around 3000 years ago. It means that 1000 BCE would theoretically be the first time that there could be one person on Earth who shows up in the family trees of everyone living now, in the year 2004. Frankly, it seems like you misconstrued the study purposely, because I can't imagine how you could possibly believe that a Professor at Yale thought Home Sapiens evolved 3000 years ago.

Dr. Solar Wolff
Friday, November 5th, 2004, 03:11 AM
I had forgotten what a bastion of flat-earthers Skadi was, thanks for reminding me, posters.

I've seen this study before, and as an amateur genealogist, I'd say it's far more than plausible.

Nordic Canadian Male, you've completely misunderstood the study (though you're not the only one). It's not saying that the proverbial "Adam" from who all humans sprung was around 3000 years ago. It means that 1000 BCE would theoretically be the first time that there could be one person on Earth who shows up in the family trees of everyone living now, in the year 2004. Frankly, it seems like you misconstrued the study purposely, because I can't imagine how you could possibly believe that a Professor at Yale thought Home Sapiens evolved 3000 years ago.

Narcissus, maybe you and Chang should read a little Anthro. history before you speak. Over thirty years ago Dr. J. B. Birdsell proposed a settlement or expansion model for sapiens. He based his model on a slightly expanding population which needed to branch off from the main group and find new hunting grounds. It was something like a two or three mile expansion per year, and he used minimal figures. Working in Australia, he calculated a total settlement by sapiens of Australia of 2,000 years. Now, nobody really cared about Australia at that time - they were all thinking of Europe during the Upper Paleolithic, but the model has now been applied virtually everywhere including the New World. Settlement and expansion were apparently rapid. This makes Chang's work a little redundant, aside from other criticisms.

Narcissus
Friday, November 5th, 2004, 03:27 AM
Narcissus, maybe you and Chang should read a little Anthro. history before you speak. Over thirty years ago Dr. J. B. Birdsell proposed a settlement or expansion model for sapiens. He based his model on a slightly expanding population which needed to branch off from the main group and find new hunting grounds. It was something like a two or three mile expansion per year, and he used minimal figures. Working in Australia, he calculated a total settlement by sapiens of Australia of 2,000 years. Now, nobody really cared about Australia at that time - they were all thinking of Europe during the Upper Paleolithic, but the model has now been applied virtually everywhere including the New World. Settlement and expansion were apparently rapid. This makes Chang's work a little redundant, aside from other criticisms.

Perhaps you are also slightly misunderstanding the study? I'm not sure I see how it has anything to do with Dr. Birdsell's findings.

Think of any person with some European ancestry. In the last 3000, everyone of them is going to connect with at least one line of nobility, mathematically and in all probability many more. For example, the typical Englishmen, or anyone with even a little English ancestry, stands a good chance of being descended from Edward III, and an almost definite chance of William the Conqueror. Edward III is a descendent of a few Emperors of Byzantium, who are descended from Armenian Kings of the early part of the first millenium AD, who are descended from Persian setraps, who are descended from one of the Egyptian dynasties of the New Kingdom; and we're back a few thousand years. It does not take a huge stretch of the imagination to imagine a modern day Persian, a Tutsi from Rwanda or a Chinese man descended from the Mongol hordes who also is descended from the Egyptian dynasties.

Now consider that this is just ONE line out of the millions and millions of ancestors that each modern human being would have living during that era. By as early as 1200, each of us has more ancestors than people living on the earth at the time. Geographical movement has nothing to do with this. This isn't a study of mass migration, it's a study of individuals. I have to admit that it's hard to imagine this working for the aboriginal inhabitants of the Americas or Australia, but it's not inconceivable; to me, it's almost a definite that it would work for anyone in Europe, Asia or Africa.

Dr. Solar Wolff
Friday, November 5th, 2004, 06:09 AM
Perhaps you are also slightly misunderstanding the study? I'm not sure I see how it has anything to do with Dr. Birdsell's findings.

Think of any person with some European ancestry. In the last 3000, everyone of them is going to connect with at least one line of nobility, mathematically and in all probability many more. For example, the typical Englishmen, or anyone with even a little English ancestry, stands a good chance of being descended from Edward III, and an almost definite chance of William the Conqueror. Edward III is a descendent of a few Emperors of Byzantium, who are descended from Armenian Kings of the early part of the first millenium AD, who are descended from Persian setraps, who are descended from one of the Egyptian dynasties of the New Kingdom; and we're back a few thousand years. It does not take a huge stretch of the imagination to imagine a modern day Persian, a Tutsi from Rwanda or a Chinese man descended from the Mongol hordes who also is descended from the Egyptian dynasties.

Now consider that this is just ONE line out of the millions and millions of ancestors that each modern human being would have living during that era. By as early as 1200, each of us has more ancestors than people living on the earth at the time. Geographical movement has nothing to do with this. This isn't a study of mass migration, it's a study of individuals. I have to admit that it's hard to imagine this working for the aboriginal inhabitants of the Americas or Australia, but it's not inconceivable; to me, it's almost a definite that it would work for anyone in Europe, Asia or Africa.

After sapiens expanded into Europe, how many individuals do you think were present? No more than 10,000. Now, imagine a population of 10,000 over a period of 30,000 years at three generations per hundred years. How closely related do you think we all are? This is nothing new. Chang wants to talk of the common ancestor of sapiens as a species and use minimum figures in a mathematical study which does not take in geography, spread of sapiens, or human mating patterns. Birdsell does a far better job indirectly explaining one variable from which a more realistic idea of inter-relatedness can be inferred.

beowulf_
Saturday, November 13th, 2004, 10:05 PM
I just see no way how a person from Europe, one from Australia and one native
American should have a common ancestor within the last 3000 years.