Late Pleostocene Human Population Bottlenecks. . . (Toba)
Posted on 04/24/2008 2:05:33 PM PDT by blam
Study says near extinction threatened people
By RANDOLPH E. SCHMID, AP Writer
April 24,2008
(AP) -- Human beings may have had a brush with extinction 70,000 years ago, an extensive genetic study suggests. The human population at that time was reduced to small isolated groups in Africa, apparently because of drought, according to an analysis released Thursday.
The report notes that a separate study by researchers at Stanford University estimated the number of early humans may have shrunk as low as 2,000 before numbers began to expand again in the early Stone Age.
"This study illustrates the extraordinary power of genetics to reveal insights into some of the key events in our species' history," Spencer Wells, National Geographic Society explorer in residence, said in a statement. "Tiny bands of early humans, forced apart by harsh environmental conditions, coming back from the brink to reunite and populate the world. Truly an epic drama, written in our DNA."
Wells is director of the Genographic Project, launched in 2005 to study anthropology using genetics. The report was published in the American Journal of Human Genetics.
Previous studies using mitochondrial DNA - which is passed down through mothers - have traced modern humans to a single "mitochondrial Eve," who lived in Africa about 200,000 years ago.
The migrations of humans out of Africa to populate the rest of the world appear to have begun about 60,000 years ago, but little has been known about humans between Eve and that dispersal.
The new study looks at the mitochondrial DNA of the Khoi and San people in South Africa which appear to have diverged from other people between 90,000 and 150,000 years ago.
The researchers led by Doron Behar of Rambam Medical Center in Haifa, Israel and Saharon Rosset of IBM T.J. Watson Research Center in Yorktown Heights, N.Y., and Tel Aviv University concluded that humans separated into small populations prior to the Stone Age, when they came back together and began to increase in numbers and spread to other areas.
Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago and the researchers said this climatological shift may have contributed to the population changes, dividing into small, isolated groups which developed independently.
Paleontologist Meave Leakey, a Genographic adviser, commented: "Who would have thought that as recently as 70,000 years ago, extremes of climate had reduced our population to such small numbers that we were on the very edge of extinction."
Today more than 6.6 billion people inhabit the globe, according to the U.S. Census Bureau.
The research was funded by the National Geographic Society, IBM, the Waitt Family Foundation, the Seaver Family Foundation, Family Tree
global warming did it! Those nomads and their SUVs.
I do not for one minute believe that 70,000 years ago man ONLY lived in Africa.
Late Pleostocene Human Population Bottlenecks. . . (Toba)
That is absurd to the maximum degree. At the end of their 100,000+ year run the Neanderthals were still around 50,000 years ago in Europe and elsewhere outside of africa. Modern man had already been around for a while at that time.
“Study Says Near Extinction Threatened People”
I tend to feel pretty dang threatened whenever anyone’s pointing a near extinction at me.
The Environmental Protection Agency saved us! Whew, that was close!
The Yellowstone super volcano exploded about 70,000 years ago. Human population crashed about the same time.
Coincidence?
Genetic collapse in such a short period points to a single calamitous event. A meteor hitting the Yucatan or the Yellowstone super volcano erupting puts millions of tons of particulate matter into the atmosphere at once, dramatically altering the climate. Global warming (or cooling) alters the climate more slowly giving plants and animals (including humans) more time to adjust to the changes. Times are tough but not nearly as tough as no sunshine and cold temperatures for a couple of years.
There have been a number of public television specials and at least one movie on the Yellowstone super volcano .
Yahoo or Google the term to find links.
P.S.: Of course, like every other one of da*n these extinction level events, its overdue to happen again. Enjoy your evening.
San people?
Did they become Arabs?
Well, it all depends on what caliber the near extinction is and if the holder looks like they know where the safety is on the thing. ;-)
“The Yellowstone super volcano exploded about 70,000 years ago”
Wasn’t that 640,000 yrs ago?
In genetic terms, this kind of extreme stress can be a great thing for a species, as only the very fittest (especially mentally resourceful) survive.
What nearly killed us probably made us much smarter.
“I do not for one minute believe that 70,000 years ago man ONLY lived in Africa.”
Maybe the implication is that we are of the generation from Africa, which survived 200,000 years (so far).
There may have been others, on other land masses, whose entire civilization disappeared. Died out from drought, from cold, from disease, from whatever.
and yet we still have liberals.
See the link in post #4...that was the Toba eruption 70-75,000 years ago. Yellowstone was 640,000 years ago.
Noah.
“What nearly killed us probably made us much smarter.”
“that was the Toba eruption 70-75,000 years ago. Yellowstone was 640,000 years ago. “
Wonder who lived there, in Yellowstone’s caldera, before being buried under tons of lava?
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