Human Beings Were Nearly Extinct 70,000 Years Ago (1 Viewer)

[chicky_pie]

IT WAS a very close call. If a devastating drought that gripped Africa had lasted just a little longer, or been a little worse, we would not be here today.

There would be no humans, no cities, no art and no science. There would be no wars and no human-induced climate change. The world would belong to the animals.

An international genetics project has found that modern humans almost became extinct 70,000 years ago.

The Genographic Project, led by American and Israeli researchers, made the discovery after undertaking the most extensive mitochondrial DNA survey ever undertaken in Africa.

In 1987 a study of mitochondrial DNA, passed down the generations via the maternal line, revealed that every person alive today is descended from one woman who lived in Africa 200,000 years ago.

The latest study shows that after the birth of humanity in eastern Africa, people quickly split into separate communities.

About 150,000 years ago humans, possibly pursuing animal herds, moved to settle throughout Africa. The number of people soared, peaking somewhere between 10,000 and 100,000.

But before the first person could venture out of Africa, the population suddenly crashed to just 2000.

"It could have been even fewer," said Spencer Wells, the Genographic Project director. "We were, in effect, hanging on by our fingertips.

"That's fewer people than there are Sumatra orang-utans today, and they are classified as extremely endangered and will probably go extinct in 20 years."

The crisis was probably caused by climate change. About 130,000 years ago the world started cooling and drying as it neared another ice age.

"There were massive droughts in Africa ... mega-droughts," Dr Wells said. With much of the continent barren and hostile, the tiny human settlements became isolated from each other.

As humanity hovered on the edge of extinction "a shift in culture began. People began making the better hunting tools they needed to survive the drought. Art makes its appearance. There is abstract thought," he said.

Then the drought broke. Isolated communities migrated and merged. With better skills and a friendlier climate, the population boomed again and people finally left Africa, spreading along the Asian coast, towards Australia.

Backed by National Geographic and IBM, the researchers, who have published their findings in The American Journal Of Human Genetics, identified humans' near demise after studying DNA mutation rates.

"By sampling people alive today, estimating how much genetic variation they have ... and knowing the rate at which variation accumulates we can say how long it took to accumulate the observed level of variation, and the size of the starting population," Dr Wells said.

The project aimed to discover what humans were doing before leaving Africa. "Three quarters of our history is virtually unknown," Dr Wells said. The research showed "there was lots going on".

He believes humanity's close shave should send a message to the 6.6 billion people alive today. "We should start to see ourselves as the lucky survivors."

http://www.smh.com.au/news/national/dry-spell-nearly-killed-us-all-off/2008/04/25/1208743202829.html

Zomg, we're all related.

 

[chicky_pie]

i dugg that

What dugg?

 

[A High Way Man]

JeSuS WaS BlAcK

 

[Gay Captain]

In 1987 a study of mitochondrial DNA, passed down the generations via the maternal line, revealed that every person alive today is descended from one woman who lived in Africa 200,000 years ago.

If they just read the Bible they would already know every person alive today is descended from one woman, Eve!

 

[Nat3skiz]

If they just read the Bible they would already know every person alive today is descended from one woman, Eve!

Yes but we're talking science. Stuff that actually happens.

 

[Slidey]

If they just read the Bible they would already know every person alive today is descended from one woman, Eve!

Old news. Toba catastrophe. It was because of a megavolcano erupting I believe, not drought.

Human population was between 1000 and 10,000 people.

Mitochondrial Eve existed 140,000 years ago not 200,000. This article is kind of inaccurate in places IMHO.

Captain: Yeah it's called Mitochondrial Eve, since only females pass on their mitochondrial DNA. She isn't the mother of all humans, she's just related to all humans. I believe it's because mitochondrial DNA is essentially static compared to the constantly evolving human genome.

You can do similar with the Y chromasome of humans, which is purely a male thing (and which is why it is degrading over time). Y-chromosomal Adam existed about 60,000 years ago.

The fact that they both lived many years apart should indicate why it isn't Adam and Eve in the traditional sense.

The Toba catastrophe helps to explain why humans are so genetically identical for a species so old, too.

 

[Graney]

I think you'll find eve was in fact 6000 years ago

 

[Slidey]

I think you'll find eve was in fact 6000 years ago

Ha Ha. No.

 

[Silver Persian]

Hmm...it would have been weird to be the children of that woman. Hello incest.

Although I guess there would have other men around to sleep with the daughters. But the sons would have to be celibate or sleep with their mother/sister :<

EDIT: Unless the sons were gay :<

 

[oo STAVROS oo]

so your telling me I'm related to coons?

wat a joke

 

[Gay Captain]

so your telling me I'm related to coons?

wat a joke

umm we already knew that before all this

 

[Slidey]

Hmm...it would have been weird to be the children of that woman. Hello incest.

Although I guess there would have other men around to sleep with the daughters. But the sons would have to be celibate or sleep with their mother/sister :<

EDIT: Unless the sons were gay :<

Arg, no! Mitochondrial Eve doesn't imply incest! It just implies that at some point in time, one woman eventually became related to every person currently alive.

It means 'most recent common ancestor' via mitochondrial DNA.

The thing to remember is that all human alive today are distant cousins. Incest only counts for about 4 blood links at most (and only 2 if all you care about is preventing mutations).

The Mitochondrial Eve changes over time, as people die, as some familial groups reproduce more than others, etc.

Further, the most recent common ancestor for all humans is younger than both Mitochondrial Eve and Y-chromosomal Adam (so younger than 60,000 years old). The true MRCA could be as young as 3,000 years ago.

Allan Wilson's naming Mitochondrial Eve[4] after Eve of the Genesis creation story has led to some misunderstandings among the general public. A common misconception is that Mitochondrial Eve was the only living human female of her time — she was not. Had she been the only living female of her time, humanity would most likely have become extinct due to an extreme population bottleneck.

Indeed, not only were many women alive at the same time as Mitochondrial Eve but many of them have descendants alive today. They may have left descendants via either son or daughters (and grandsons or granddaughters, and so on). Nuclear genes from these contemporary women of Mitochondrial Eve are present in today's population, but mitochondrial DNA from them is not.[1]

What distinguishes Mitochondrial Eve (and her matrilineal ancestors) from all her female contemporaries is that she has a purely matrilineal line of descent to all humans alive today, whereas all her contemporaries have at least one male in every line of descent. Because mitochondrial DNA is only passed through matrilineal descent, all humans alive today have mitochondrial DNA that is traceable back to Mitochondrial Eve.

 

[Silver Persian]

Thankyou for clarification ^_^;

 

[wuddie]

this gives raise to another thought - what if there was another specie of intelligent being on earth, one which is of higher order, lived at the same time as our ancestors. but maybe they've extinct for whatever reason. human have always seen themselves as the head honcho of the animal kingdom, but what if that wasn't the case x years ago?

it is fasincating. anyone wants to contribute to this thought?

 

[Raven3333]

this gives raise to another thought - what if there was another specie of intelligent being on earth, one which is of higher order, lived at the same time as our ancestors. but maybe they've extinct for whatever reason. human have always seen themselves as the head honcho of the animal kingdom, but what if that wasn't the case x years ago?

it is fasincating. anyone wants to contribute to this thought?

If there was another species ovbiously they where not that smart considering they couldn't prevent their own extinction. Clearly humans are the head honcho, as you put it, in this world.

 

[Gay Captain]

We aren't the head honchos in this world, bacteria are

 

[wuddie]

i put it down to luck, pure luck. surely human didn't know what was going on back then, so how can they do anything to prevent from extinction?

 

[Nat3skiz]

i put it down to luck, pure luck. surely human didn't know what was going on back then, so how can they do anything to prevent from extinction?

Your poor grasp of english and reasoning leads me to believe you will also soon be extinct.

 

[P_Dilemma]

We aren't the head honchos in this world, bacteria are

Yea, bacteria are awesome, without them we wouldn't have alcohol :rofl:

p__D

 

[wuddie]

Your poor grasp of english and reasoning leads me to believe you will also soon be extinct.

say what now? and your grasp of english and reasoning is far superior?