Study says near extinction threatened people

[ben_meyers]

Source: Yahoo News

WASHINGTON - 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."



Read more: http://news.yahoo.com/s/ap/20080424/ap_on_sc/close_call

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That may have been close! Will it happen again?

[LakeSamish706]

1. I would say undoubtedly that we are on the verge of it now one way or another. n/t

[gateley]

2. This is fascinating --

I wonder if it WILL happen again.

[TomInTib]

5. If it does...

I hope the next White Race emerges with a better sense of rythm.

[murray hill farm]

7. Hahahahahahaha!

Too funny!

[slackmaster]

6. A severe, prolonged drought in eastern Africa would be a huge regional humanitarian crisis

As it would anywhere. But it would not threaten the global human population.

[XemaSab]

25. A collapse of industrial agriculture would be a HUGH bummer worldwide

It might not lead to a near-extinction event, but if the population crashed by 90%, in some areas there could be regional "bottlenecks."

[ohio2007]

29. maybe drought is the "normal" climate for Africa

[slackmaster]

36. It seems to be normal for Southern California

:argh:

[angstlessk]

3. I guess the result was a hardier group of humans, maybe able to withstand

this new conflagration?

[TomInTib]

4. Oh, this oughta go over big with the nutjobs.

Back to Africa again, eh?

[DrDan]

8. the drought was a result of a super-volcano

similar to the one under Yellowstone today.

Well - this according to a History Channel show a couple of nights ago.

(Have not read the article yet - but will soon to see if the super-volcano theory is mentioned.)

[Hydra]

17. That's what I heard too

And Yellowstone is 40,000 years overdue. She'll probably go any time now.

Had it gone sooner, we probably would have been decimated or perhaps wiped out entirely before this. In fact, that may have happened at various times before- we start getting somewhere, and a planetwide natural disaster pushes us back to almost nothing.

Something to think about.

[Viva_La_Revolution]

31. Toba eruption...

another theory is several bottlenecks at the same time..

The Multiple Dispersals model proposes a population bottleneck occurred when cold, dry climates isolated populations in Africa. Additional bottlenecks occurred through physical bottlenecks such as the Sinai Peninsula. The first dispersal of anatomically modern humans, to the Levant around 100,000 year ago, is evidenced by early modern human skeletons in the Near East. According to Ambrose, this first dispersal apparently failed to permanently establish modern humans outside of Africa. Genetic evidence shows that non-African populations can be divided into southern Australasian and northern Eurasian populations that divided 50-75,000 years ago.

In contrast, Ambrose's model proposes a scenario of a globally synchronous bottleneck. If bottlenecks were caused by the cold climate, duration was approximately 10,000 years with release 60,000 years ago. If the eruption of Toba alone caused the bottleneck, then release may have followed within a few decades of the volcanic winter 71,000 years ago, or the bottleneck could have lasted 1000 years, during the coldest portion of the Ice Age following the Toba eruption. In the bottleneck scenarios, more individuals survived in the African tropical refugia, resulting in the greatest genetic diversity survival in Africa.

Ambrose concludes that bottlenecks occurred among genetically isolated human populations because of a six-year long volcanic winter and subsequent hyper-cold millennium after the cataclysmic super-eruption of Toba. This volcanic winter played a role in recent human differentiation. The resultant combination of founder effects and genetic drift may account for low human genetic diversity as well as population differences associated with so-called races. The bottleneck hypothesis offers an explanation for why humans exhibit so little genetic variation, yet superficially appear diverse. It also affords an explanation for the apparent recent coalescence of mtDNA and African origins.
http://www.jqjacobs.net/anthro/paleo/bottleneck.html

[daleo]

9. Global nuclear war could do it

So could catastrophic global warming, or an asteroid strike.

[tridim]

12. I believe we'll survive anything short of the Sun exploding

I'm not saying we'll thrive, but some will certainly be equipped to survive almost any major global disaster.

[balantz]

16. Only people like Cheney deep in well stocked bunkers

could survive world-wide, thermonuclear war. And he and his kind would have to stay under there for generations likely becoming a blind race of mutant worms!

[XemaSab]

26. "Becoming" a blind race of mutant worms?

:shrug:

[balantz]

27. After the shedding of the human-looking exodermis.

[razors edge]

32. Yes, they will refuse to evolve after all.

[balantz]

10. There is plenty of reason to doubt that humans will survive for much longer.

As we contribute to the destruction of life on this planet we seem to forget that includes us as well.

And then, if that fails, there is religious fanatacism and thousands of nuclear weapons at the ready for diabolical brains to figure out how to unleash for their glorious "day of judgement". The only judgement will be annihilation of Earth's organisms, including humankind. The judgement of no more life here.

[alfredo]

15. Most great civilizations died out because they used up resources and

were forced to move on to other regions. Our problem now is we are running out of places to go.

We really need a culling of the herd to ensure the long term survival of the species. Wars are not efficient, AIDS never lived up to its promise, same with the bird flu. Mass starvation seems to be the best means to reduce overpopulation. ZPG never worked because of that damn "breed ourselves into dominance" mentality of religion and other tyrannical regimes.

Deer populations go through expansions and collapses of population and they've thrived. We are subject to the same laws of nature.

[bluerum]

22. Presumably we are smarter than deer and can plan ahead ---

but I still have not seen any convincing evidence.

[alfredo]

24. You've heard the term, "creature of habit"?

We can't rise above our genetic code. We can't turn off behaviors that are hardwired in us. We can be like jazz musicians, and improvise on a theme, but most people play the music as written.

[arundhatiroyfan]

35. I think you're wrong.

While the earth can't take an infinite amount of people, it just makes no sense to reduce human population by means of starvation. To let such a thing happen would backfire massively imo.My apologies if that wasn't your point.

[Uben]

11. It's not if, but when......

The human race will be obliterated at some point. The only possibility of survival is populating another planet. We will be hit by another asteroid that will wipe out at least 90% of life on our planet.

[yodermon]

13. So much for Noah's Ark!

sounds more like Noah's Drought. :rofl:

[ramapo]

14. I bet Mother Earth is pissed off she missed her chance

She sure would've prevented a world of hurt to most of the denizens of this fine planet.

[Karenina]

18. Don't misunderestimate her!

:evilgrin:

[gateley]

19. I've heard someone say she'll shake us all off --

like a dog with fleas.

[Karenina]

20. And , of course you know the old joke

about two planets whose orbits meet again after millenia...

A: LONG TIME NO SEE! How ya been? You're looking a bit bedraggled...

B: Good to see you too! Not feeling so well lately... I got me a BAD CASE of Homo Sapiens.

A: Been there, done that. Don't worry yourself. They go away!

[gateley]

33. Ha! I'd never heard that -- thanks!! nt

[tavalon]

23. I use the cancer analogy

We are a cancer upon the body of Gaia. She will have to rid herself of us or die and she isn't going to die. She lives in a different time, measured in millenia and we are just a short time upon this living rock.

[gateley]

34. Good analogy. nt

[bluerum]

21. But wait - the bible says we were put here 10,000 years ago. How can we

reconcile that with genetic evidence?
:sarcasm:

[ohio2007]

28. global warming 70,000 yrs ago? who knew ?

what other cause could lack of rain in Africa be from?

[depakid]

30. More hooey from the out of Africa geneticists

"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 fossil evidence shows otherwise- humans were already in Australia at least 60,000 years ago!

http://www.jqjacobs.net/anthro/paleo/australia.html