Mankind's Close Call With Extinction

DNA Evidence Reveals How Humanity's Stone-Age Almost Went Way Of The Dodo

(AP)  Human beings may have had a brush with extinction 70,000 years ago, an extensive new genetic study suggests.

The number of early humans may have shrunk as low as 2,000 before numbers began to expand again in the early Stone Age, according to an analysis released Thursday.

"This study illustrates the extraordinary power of genetics to reveal insights into some of the key events in our species' history. 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," Spencer Wells, National Geographic Society explorer in residence, said in a statement.

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, New York, 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 of one another.

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 DNA and Arizona Research Labs.

[talkingham]

I don''t buy it. I think they are looking through the wrong keyholes at very small samples designed to fit their theories.

[mcvet]

I don''''t buy it. I think they are looking through the wrong keyholes at very small samples designed to fit their theories.


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Posted by talkingham at 12:49 PM : Apr 24, 2008
+ report abuse

What don''t you buy... what part of the study? It appears to me they have taken apart the DNA and determined the facts they present. Please tell me you aren''t one of those people who will convict a man to die based on DNA but refuse to accept findings is it doesn''t fit your religion.

[mwhc1]

I agree with talkingham... and the earth is flat... and god made the everything in seven days...

[thinkharder-]

I don''''t buy it. I think they are looking through the wrong keyholes at very small samples designed to fit their theories.
Posted by talkingham at 12:49 PM : Apr 24, 2008

I think you have the wrong idea about how science works. You see, you don''t typically come up with a theory (particularly one as detailed and elaborate as the one above) and then design your experiments in such a way to show preference towards your fabrication. That''s religion''s job. What these scientists have done was to simply observe what occurs in nature, particularly at the molecular (DNA) level, and take those observations and use them to create a picture of our history with a level of confidence proportional to the weight of the observations made. That is science.

[rushlimpdrug]

This sounds like a bunch of krap.

So they have it down to one "Eve"?

Sure Bob.

Whatever you tell me.

[sentry88]

everyone of us has EVE''S dna we are from her.

[kommoncents-2009]

You can''t argue with ignorance, and religion = ignorance.

[rudy2281]

Science & religion=people: They always ''have it right this time'' only to revise or overturn their findings a couple years later. As marvelous as our brains are, we can no more fathom what happened or what will happen than a grain of beach sand can fathom the great storm on Jupiter.

[extremophil]

"Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago"

Man, that Global Warming just won''t let up.

[lloydbest1]

I won''t say yea or nay but it could have happened. Here''s how:
The earth was already at the height of the Pleistocene glacial advance. Global temperatures may already have averaged as much as 8 to 10 degrees F lower than today''s.
A massive volcanic blast at Lake Toba in Sumatra during the time the bottleneck was said to have occurred may have temporarily dropped global temperatures temperatures another 8 to 10 degrees F. Given that the worst case scenario would yield a planet that averaged a temperature only a little bit above the freezing point of water, I would guess the wild game and other food sources sapiens (and their Neanderthal and Heidelberg cousins) depended on would very suddenly have been in extremely short supply.
Let''s not underestimate the effect this super-eruption had. It was graded as the most catastrophic eruption the Volcanic Explosivity Index has. The only other blast in the last 25 million years that MAY have been worse was the Lava Creek eruption at Yellostone - 650000 years ago.
Krakatau is the gold standard by which all other volcanic bangs are measured. In historic times, only the Santorini blast 1500 years BCE and the Mt. Tambora thing that caused the "Year without a summer" were worse; and Santorini was only about 3 times as bad.
Toba was a minimum of 2000 times as explosive and I can easily see how such a thing could have had a massively negative impact on a human population already stressed by a deteriorating climate.

[locke10]

Just to say: the dodo would not have gone "the way of the dodo" if it had not been for humans. Check these things before you print it, CBS.

[speakinup]

"Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago"

Man, that Global Warming just won''''t let up. Posted by Extremophil


Ain''t THAT the truth. Wonder if Eve''s SUV was burning too much hydrocarbons. If only they had backed off on the polution - think of all the polar bears that would have been saved.

[obamasgranny]

I thought this article was going to be about what would happen if Obama is elected!!

[davide73-2009]

The comments above show both the best and worst of what man has become since his near escape.

[superdem]

I hate to tell you but Eve was no buxom blonde hottie. She was a monkey girl about three feet tall who ate bugs while trying to stay away from the leopards.

[kommoncents-2009]

*Obamasgranny* THAT WAS A GOOD ONE! HYSTERICAL!!

[usbrit-2009]

Posted by LloydBest1 - thanks for the great input Lloyd.

[denn034]

Yeah, mankind had a close call with extinction but, that occurred at the time of the worldwide flood mentioned in Genesis 6 not earlier.

[talkingham]

You''re wrong ThinkHarder. I work with a bunch of genenticists and I don''t like ''em. They are pretentitious to the point of boredom and overconfident in rather filmsy methods that don''t provide the clear picture they claim to report. And in science, it''s called "modelitis" when scientists shape their methods to fit an outcome they perceive as being more *** than plain scinece.

[usbrit-2009]

You''''re wrong ThinkHarder. I work with a bunch of genenticists and I don''''t like ''''em.

Posted by talkingham

What exactly do you do with these genenticists you don''t like.

[lvdragonlady-2009]

I think they are wrong. How did 2000 people in Africa become ''US'' today. Does not make sense. I want more details because what they are givng us in this article is not enough to justify their statement.

[jcr103]

I think they are wrong. How did 2000 people in Africa become ''''US'''' today. Does not make sense. I want more details because what they are givng us in this article is not enough to justify their statement.

Posted by lvdragonlady

Maybe you should go download the scientific article in the American Journal of Human Genetics and read it then.

[bobbyduck1]

Hmm...interestingly science has now identified an "Eve" that all humanity descended from, and a period of near extinction some time much later. Gee whiz if that story doesn''t match the Bible accounts of creation and the great flood! Now all we have to do is figure out how "science" got the dates wrong!

Kind of like when "science" knew for sure the Bible was fairy tales because there was no such person as Nebuchadnezer....then one day they dug him up! Ends up that only the Bible carried that bit of history for many generations.

[Marie Zarankevich]

Dear denn034 -- Somewhere in you Bible it tells you to ''Seek The Truth''. -- You cant do that without opening a few OTHER books, ya know? -- ;

[Marie Zarankevich]

Your religion is no excuse for your profound ignorance. -- You all could become informed people, but you prefer to glorify laziness into a religious act. -- Not bothering to study in school is not a religious act! -- You should be ashamed of yourselves for not using the minds that God gave you. -- You were given them for a reason.

[displeased]

Gee whiz if that story doesn''''t match the Bible accounts of creation and the great flood!
Posted by bobbyduck1

I thought they said it was a drought?

[davewrite1]

Unfortunately, too many are ignorant not only about science, including genetics, but also are enumerate. Ergo: Scientific revelation, backed by mountains of supporting evidence, baffles most folks. What what needs to do is understand is the power of doubling. Start with 2,000 and then double it for every 20 years, and you''ll arrive at a startling large number. You can also do the reverse: Each of us have four grandparent of which each had four grandparents: 4, 8, 16, 32, 64, 128, 256, 1028. Do that for even a mere 500 generatons and you''ve got over a million grandparent. Carry it our father and you''ll see why we''re all related. Race is a social construct, for example, not a biological realty.

[incog-nito]

Phew! That was a close call. I feel so much better now knowing that we made it. Don''t know about you, but personally I would feel very upset if I were to find out that humans didn''t make it.

[Marie Zarankevich]

Race has only to do with how far from the Equator your ancestors migrated. -- We''re all of African descent.

[dredre2k]

I think they are wrong. How did 2000 people in Africa become ''''''''US'''''''' today.---- JCR103

As Modern Humans left africa and migrated to different parts of the world, skin color changed depending on the latitudes people reached away from the equator. Human beings at the equator (africans, indians, sri lankans) over a period of time adapt to the high UV and high amounts of sunlight with darker skin. Human groups (europeans, chinese) who live at higher latitudes need lighter skin so that the body can absorb the appropriate amount of sunrays... Sunlights prevents rickets. If humans at higher latitudes had dark skin, they''d be more prone to getting rickets because the sun doesn''t shine as often in the north/south.

People''s height, size, and appearance also changed as they moved throughout the globe. THUS, that''s how african Humans became the rest of the world.

All of our descendants were african. We all have african lineage. :-)

Hope that helps!

[usbrit-2009]

You can find more on this theory at -

en.wikipedia.org/wiki/Toba_catastrophe_theory

[mecury69]

You mind explaining what branch of ''science'' would be attributed to Nebuchadnezzar''s existence. Sounds like history to me.

[incog-nito]

It''s a good thing the web is anonymous. Otherwise some people here would be laughed right out of town.

[mecury69]

think they are wrong. How did 2000 people in Africa become ''''''''''''''''US'''''''''''''''' today.---- JCR103

And what is this opinion based on? You must have a theory or idea as to why it would be untrue.

[andrew_693]

great article

[irliberal]

But but but I thought the great flood was mankind''s great escape from extinction. But Noah saved us... right?


LOL

[inventagod2]

Oh, lord - stinkinrickky is missing out on a good one...
someone drag his soapbox over here

[bobbyduck1]

babykilller:

You might note that I didn''t espouse beliefs, simply talked about some reported apparent facts and some of what the Bible says. From that you concluded that I''m a religious zealot, Bible-thumping, closed-minded moron with a backwards agenda. Umm this might be a case of (you) the pot calling (me) the kettle scorched.

I too read and treasure many different kinds of books, writings and other ideas. I am not a zealot or even a very carefully practicing Christian, don''t associate with any religion regularly and don''t Bible thump.

But you failed to comment, in your closed-minded rant about fairy tales, on the parallels that were the subject of my post. I guess when you are too busy espousing anti-whatever it is you are against rhetoric, there is no time to consider the topic that was actually raised - the parallels between "science" and the Bible accounts. Try again?

[Syndicate]

I think we may be looking at the birth of modern humans, rather than an possible extinction event. Perhaps one requires the other. The small population would have increased the rate of evolution. Since new genes would be able to spread throughout a small population very quickly.

Bobbyduck1: The flood happened 12,000 years ago when the ice age ended. It wasn''t a complete flood but to people of that day it probably seemed that way. their are older text that prove the biblical story is not entirely accurate. there is also an mtDNA eve for humans and chimps but I doubt you will embrace that one.

[jcr103]

Did you notice the picture accompanying the article? The shadow of the woman...she''s hot!!!

[bobbyduck1]

cbscrash07: You''d probably be surprised at what I would/do or wouldn''t/don''t accept/believe. It seems that as soon as anyone mentions the Bible as any kind of reference, the majority immediately classify that person as belonging in either nursery school or at a religious camp or something.

Personally I think the accounts of creation and the great flood are a means for a very advanced intelligence to relate important events to a very un-evolved audience, that being all of humanity at the time these early telling/writings took place.

But I also think that the evolution of all of the interwoven complex beings and their societies - both "animal" and "human" was no accident of nature.

Suppose for a moment that "God" "created" human life on earth via DNA manipulation and/or some other means that we haven''t learned of yet. Now to explain all of that to the slowly evolving results of this "creation" you would need some nursery-rhyme type simplicity when you set down to talk to them about it. My opinion (and it''s only that) is that this is kind of what happened. It''s perhaps why creationists and evolutionists can''t give up their core beliefs, they are both kind of right. In my opinion.

What if "human-ness" was introduced into one (or even several) relatively high-level animal species on earth via DNA manipulation. Could that not be explained by what we see around us? Just food for thought, I don''t have the answers but at least I know it.

[tlobe]

I''m no longer convinced that we all evolved from Lucy. If onditions were right on the African continent for early humans to evlove from other species, then were those same conditions likely present at other dispersed locations. We would all have similar genetic codes since we are all advanced biped homosapiens. If the earth has had many past climatic changes due to comet and/or meteor impacts, then it makes sense that the population of the human species would have ebbed and grown. I am sometimes amazed at science frequently overcomplicates simple things.

[gaye5]

Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago.

Oh my gosh, dont tell me that global warming happened then..oh no dont tell me that we have gone through many cycles of this..
I am printing this with tongue in cheek and of course we have, many scientists have reported that we have gone through cycles of great climate change before, but the media wont print it as it is not popular for the global warmers of today and the money that will be made out of this scam..remember that Vikings used to be able to grow crops in Greenland, but cant now.

[gaye5]

How on earth can they conclude that humans separated into small populations prior to the stone age, then they came back together and began to increase in numbers and spread to other areas.
The bones of perhaps 99% of any living things disappear within a few years of dying. There could have been masive populations then and they have all become dirt.. Humanity has a great capacity to adapt and survive.. I cannot see how anyone can deduce the population of thousands of years ago, there were no records to tell us and now no bones.. Tomorrow someone else well qualified, will come out and tell us that we were over populated back then or something... I object to having my well earned taxes spent on speculation like this which cant be proved one way or the other, surely there is more worth while things to be studying like destroying cancers..

[prohb]

Gaye5 continues the same old mantra of the naysayers -"See! There were cycles in the past!" Of course there were! No reputable scientists denies that. But...because of human activity we are making this cycle worst and jump-starting some really bad effects. Look at the ice core data and the studies about the synergistic effect of the water vapor and CO2 in the atmosphere.

[incog-nito]

This article is false. If humans were to become extinct 70,000 years ago, the aliens would just come back and drop off a few more, and start all over again.

[jimfinster]

gaye5:

Take a basic geology course and you WILL understand. Good luck.

[newsterl]

y. 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"

Yeah, and now we are rapidly destroying the planet by TOO MANY being born!

[brianbwb-2009]

Posted by bobbyduck1

Let us continue your line of supposition, suppose that subsequent generations re-interpreted and twisted the original information, to fit more mundane agendas such as greed, and power-hunger, until it was so far from the truth as to be opposed to all empirical evidence, and those re-interpretations were accepted as the original truth, which of course by that time is empirically incorrect.

At that point, does not the re-interpreted information become irrelevant, useless, and serving of the opposite purpose of which it was originally intended?

[rational_1]

This article is false. If humans were to become extinct 70,000 years ago, the aliens would just come back and drop off a few more, and start all over again.
Posted by incog-nito at 11:05 PM : Apr 24, 2008

Hmmm, an interesting hypothesis. I propose an extension; the spaceship is made of wood and shaped like a gigantic boat and has pens for two of each kind of animal. I love doing creation science - you just say whatever pops into your mind and you don''t have to provide any evidence. Can I have tenure at the Institute for Creation Research now?