Early humans had a brush with extinction

[Keith P]

http://www.cnn.com/2008/TECH/04/24/c....ap/index.html

WASHINGTON (AP) -- Human beings may have had a brush with extinction 70,000 years ago, an extensive genetic study suggests.
art.spencer.wells.ng.jpg

Geneticist Spencer Wells, here meeting an African village elder, says the study tells "truly an epic drama."

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 that 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," said Spencer Wells, National Geographic Society explorer in residence.

"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.

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, who 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, New York, and Tel Aviv University concluded that humans separated into small populations before 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 researchers said this climatological shift may have contributed to the population changes, dividing into small, isolated groups that developed independently.

Paleontologist Meave Leakey, a Genographic adviser, asked, "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.

[Bearcatt]

thats crazy man you know it could happen again but i dont think we will ever drop down to 2,000.. still wild

[Keith P]

Originally Posted by Bearcatt

thats crazy man you know it could happen again but i dont think we will ever drop down to 2,000..

A plethera of things both man made and natural could easily dwindle down the population to nil to non.

You should read this book for a...kind of good time:

http://www.amazon.com/Earth-Abides-G.../dp/0449213013

[Enchilada]

Every species will someday be extinct. Fact of Life.

[zerojunkie]

I'd heard that they think it was related to some massive volcanic eruption around India. There was a two-part documentary on cable about this a few months back, very fascinating.

[PETA]

I thought this was old news? That we'd used DNA reduction studies to find two distinct populations that we could identify as living on opposite sides of some lake in what... the Sudan I think?... and that our gene pool evolved out of that?

Still... amazingly interesting stuff

[-m-]

Everyone knows the great flood almost wiped out man. THANKFULLY Noah was there with his ark to save the day.

[PETA]

Miles... you're going to hell!!!

[Keith P]

Originally Posted by xian

I thought this was old news? That we'd used DNA reduction studies to find two distinct populations that we could identify as living on opposite sides of some lake in what... the Sudan I think?... and that our gene pool evolved out of that?

Still... amazingly interesting stuff

Ah yes I remember now. Maybe just a rehashing of the study or going a bit more in depth then.

[Coyotl]

Originally Posted by zerojunkie

I'd heard that they think it was related to some massive volcanic eruption around India. There was a two-part documentary on cable about this a few months back, very fascinating.

yeah supervolcanoes are a bitch. supposedly the heralds of mass extinction many times in the earth's history. i would be willing to bet that would be the most likely cause of the bottlnecking of our early gene pool.
the next time the yellowstone caulderon explodes it will blanket the entire western united states in 6 feet of ash, and block out the sun for at least 5 years.

[PETA]

Originally Posted by Keith P

Ah yes I remember now. Maybe just a rehashing of the study or going a bit more in depth then.

Does it ring a bell? Because I can't seem to put a finger on it exactly... except that it had to do with some very old fosil discoveries a few years back? Like I said, regardless... this shit is always fascinating. For better or worse I bet in our lifetime we have a mitochondrial dna family tree of the majority of people alive and then it'll start working its way backwards further and further into our ancestry...

they already exist as far as largely defined ethnic groups go... probably more narrowly defined than I am aware actually... mitochondrial anthropology? Is that a discipline? Should be if it isn't.

Originally Posted by PatMeetsPsy

yeah supervolcanoes are a bitch. supposedly the heralds of mass extinction many times in the earth's history. i would be willing to bet that would be the most likely cause of the bottlnecking of our early gene pool.

the next time the yellowstone caulderon explodes it will blanket the entire western united states in 6 feet of ash, and block out the sun for at least 5 years.

is a "super" volcano the same as a fault line eruption? See the Siberian Traps.


oh.... and are you guys referring to the Toba Eruption in Indonesia? Not India?


and "caldera"

[Keith P]

Originally Posted by xian

mitochondrial anthropology? Is that a discipline? Should be if it isn't.

Don't think its actual discipline but looking at google it seems a common research tool.

[zerojunkie]

Originally Posted by xian

is a "super" volcano the same as a fault line eruption? See the Siberian Traps.


oh.... and are you guys referring to the Toba Eruption in Indonesia? Not India?


and "caldera"

That's it, and yes i believe the traps and yellowstone are the same kind of volcanoes. Pretty rough stuff...by the way, i remember reading they used mitochondrial DNA to trace all blue-eyed people to one common ancestor...yeah, if you have blue eyes and banged someone else with blue eyes...ha ha

[BrandonWhat]

Originally Posted by Dixon Cox

Every species will someday be extinct. Fact of astrophysics and geology.

Fixed. And we'e got about 15,000 years to find a way out of here and onto a different rock, unless the Earth, the Cosmos, our own stupidity cause something to happen before then.

[PETA]

Originally Posted by zerojunkie

That's it, and yes i believe the traps and yellowstone are the same kind of volcanoes. Pretty rough stuff...by the way, i remember reading they used mitochondrial DNA to trace all blue-eyed people to one common ancestor...yeah, if you have blue eyes and banged someone else with blue eyes...ha ha

lol - 4 of us in this house


you shouldn't mess with me.....Ill ruin everything you are...I'll give you television, I'll give you eyes of blue, I'll give you men who want to rule the world