New Out-Of-Africa Theory Unveiled

Everyone outside of Africa — Asians, Europeans, Native Americans, Southeast Asians, Australian Aborigines, etc. — came from the same small band of humans that left the mother continent some 80,000 years ago by way of Ethiopia, according to a new theory unveiled Monday by geneticists and DNA detectives.

"No, we haven't found the bones of the original Eve," said DNA tracker Stephen Oppenheimer of Oxford University in a press teleconference.

Instead, researchers have followed the trail of mitochondrial DNA, which we inherit unchanged from our mothers, and backtracked down the branching tree of the human family throughout the world.

If the mitochondrial DNA story is correct, then we all descend from a woman who lived in Africa 150,000 years ago, said geneticist Martin Richards of Huddersfield University in England, who also took part in the briefing.

Oppenheimer and Huddersfield will appear in "The Real Eve," a Discovery Channel documentary premiering on April 21.

What's more, all non-Africans come from a small group of people who ventured out of Africa some 80,000 years ago, perhaps because of climate changes along the Red Sea shore that made life there too difficult, he said.(maybe it dried up during the Ice Age, huh?)

Genetic evidence of that small band can be found today in India, said Oppenheimer. "In India, all of the early lines that gave rise to Asians and Europeans are found in great profusion and great antiquity," he said.

For years anthropologists have debated whether humans left Africa by a northern route — via the present-day Suez Canal region — or by a southern route, via a short-lived isthmus connecting Ethiopia to Yemen at the southern end of the Red Sea. Some researchers have even suggested that Europeans descend from the people of the northern exodus and the rest of non-Africans from the people of the southern exodus.

"The fact that we look different is because we live in different environments," said Oppenheimer. "(But) we are really, truly the same under the skin."

The single exodus theory also meshes well with other genetic and archeological discoveries. Last year, researchers working on the Human Genome Project reported that the pool of human genetic material is startlingly small, implying we are a young species and come from a very small group of Africans.

However, not everyone is convinced of the single group theory, said paleontologist Tim White of the University of California at Berkeley. "My sense in it is that we're not close to the bottom line yet," he told Discovery News.

Genetics has yielded some new data to the mix, he said, but the smoke hasn't yet cleared enough to see the details of exactly when and where modern humans came out of Africa.

By the way, thanks for the ping.

Just by way of timing for the last Pleistocene glacial event, oxygen-16/oxygen-18 ratio studies from ice cores in Greenland and the antarctic tend to show a similar trend. The end of the last interglacial (warm period) came about 125,000 years before the present (b.p.). There was then a general cooling trend until about 100,000 years b.p. From 100,000 b.p. to 85,000 b.p. there was a slight "warming" but the raios still indicate a cool period. The ratios then drop off again and reach a minimum about 20,000 years ago. That point is generally considered to be the "height" of the last Ice Age. Since then there has been a steady warming trend. Today the oxygen isotope ratios are about what they were 125,000 years ago.

The melting of the North American and Asian ice sheets would readily explain the jump in eustatic sea level from the lows at 10,000 b.p. to the levels of 6,000 b.p. - which are near the levels of today.

I believe the evidence of from the oxygen isotope fluctuations and eustatic sea level change will certainly figure into the development of early human societies.

That, sir, is a softball. I have been in science my whole life and have a great deal of respect for data.

Whats that make you, a pharmacist?

When politics drives pronouncements based on contradictory data it ceases to be science. Stephen Jay Gould is the mother of all anthropology/evolution liars. They disregard contradictory evidence (and there is much).

Don't know about Mr. Gould, his research practices, or whether he's a liar, or not. I suspect you may have some shortcomings of your own regarding contradictory evidence.

Further, I infer from your question that you think I have an ulterior motive in lambasting this lunacy, i.e., I am a racist.

I didn't think you were a racist, but I had a suspicion. Glad to hear from you that such is not the case. Racist posts give credence to liberals, who wish to give this forum a bad name.

You, perhaps are a liberal. Read more on the subject starting with the site I linked.

Sorry I can't reinforce your particular prejudices, but I'd probably be considered middle right by everyone except evangelicals (no disrespect to fundementalists intended) Ideologues can also give this forum a bad name.

You do not sound like a mensch to me.

Yawn... Howcome everyone with whom I have the temerity to question, arrives at the same conclusion, stated more or less the same way? I do, or do not, agree with you hence I am, or am not, a Mensch?

Further, I infer from your question that you think I have an ulterior motive in lambasting this lunacy, One has to be very careful making inferences from questions: the question's author reveals nothing but his or her curiosity.

i.e., I am a racist. A bit extreme, wouldn't you say? One could also infer that you, like the scientists you justly criticize, may be married to an alternative idea --- such as multi-regional origin, for instance. No one has implied that you are a racist thus. Were Mensch to do so, you would be rightfully offended; he did no such thing, however.

You, perhaps are a liberal. All this is referred from Mensch's question? And, despite the contradictory evidence that he, Mensch, is spending time on this, rather than some liberal, board?

You do not sound like a mensch to me. Again, all this is inferred from a question? A respect your scientific honesty and that, as you write, you "have been in science [your] whole life and have a great deal of respect for data." It is not that often that well-trained scientists have problems with data --- it is misapplication and illogical conclusions drawn on the basis thereof that gets them in trouble.

It is sad for me to see two clearly intelligent and scientifically honest people being on the verge of calling each other names on the basis of what has not been said.

Actually, both of you look like mensches to me.

ME: That, sir, is a softball. I have been in science my whole life and have a great deal of respect for data.
YOU: Whats that make you, a pharmacist?

ME NOW: There you go again, making an INCORRECT inference. No--I am not a pharmacist, but would not be ashamed if I were one. Not only are you wrong AGAIN, but you show your prejudice agaist someone you think is not as bright as you are, or perhaps does not make as much money as you. Shame on you.

ME: When politics drives pronouncements based on contradictory data it ceases to be science. Stephen Jay Gould is the mother of all anthropology/evolution liars. They disregard contradictory evidence (and there is much).

YOU: Don't know about Mr. Gould, his research practices, or whether he's a liar, or not. I suspect you may have some shortcomings of your own regarding contradictory evidence.

ME NOW: If you do not know who Gould is then you cannot be very well read in this subject matter. The scientific method (which--if you are not schooled in science please look up) advances by looking at data and putting forth hypotheses which can be falsified by experiments. Unfortunately, much in the way of paleoanthropological data CANNOT be falsified and therefore must remain quite speculative. I do NOT ignore good data; if I did, the whole basis of my worldview and intellectual honesty would be BS. This I will not do wherever the facts take me...this is why I rail against the pc pseudo-scientists. And BTW: there is NO DOUBT WHATSOEVER that humanity emerged from Africa. What the debate about has to do with details and timing.

ME: Further, I infer from your question that you think I have an ulterior motive in lambasting this lunacy, i.e., I am a racist.

YOU: I didn't think you were a racist, but I had a suspicion. Glad to hear from you that such is not the case. Racist posts give credence to liberals, who wish to give this forum a bad name.

ME NOW: Well...merely having a problem with PC data makes you suspicious that I am a racist. Some advice: before you do that to a poster on this or any other forum, check out their other posts to see if there is a pattern. Another illustration of the scientific method of checking out an hypothesis (i.e., "suspicion").

ME: You, perhaps are a liberal. Read more on the subject starting with the site I linked.

YOU: Sorry I can't reinforce your particular prejudices, but I'd probably be considered middle right by everyone except evangelicals (no disrespect to fundementalists intended) Ideologues can also give this forum a bad name.

ME NOW: Goodness: everything gives this forum a bad name except you. Any nosebleeds atop that high horse?

ME: You do not sound like a mensch to me.

YOU: Yawn... Howcome everyone with whom I have the temerity to question, arrives at the same conclusion, stated more or less the same way? I do, or do not, agree with you hence I am, or am not, a Mensch?

ME NOW: Okay--this may be difficult for you so I will type s-l-o-w-l-y: You did NOT "question" me on facts or substance; you questioned my MOTIVES and implied a racist undertone to my post. That is acting like a liberal and therefore I assumed if it walks like a duck, etc. Have a pleasant PC day.

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