Humans nearly went extinct

[Cancer]

Fodder for world-making....

 

This is mentioned in Science Now for yesterday (19 Jan 2010). Statistics on the genetic variability in modern humans suggest that 1.2 million years ago the breeding population of humans worldwide bottomed out around 18,500 (an uncertain number, but certainly no larger than 26,000). Humans now have a remarkably small genetic variability compared to other apes, and this is a signature of a species that barely eluded extinction in the evolutionarily not-too-distant past. That time is before modern humans (which arose 200,000 years ago); it's back in the Homo erectus era. There have been other suggestions that humans later went through near-extinction events, too.

 

For comparison, current world populations of the (endangered) species of chimpanzees and gorillas are about 21,000 and 25,000 respectively.

[austenandrews]

Re: Humans nearly went extinct

 

One wonders how much such an event influences later evolution. Could it have been pivotal in creating such an exceptional species as us?

[Cancer]

Re: Humans nearly went extinct

 

My gut tells me that the evolutionary "inertia" of a small-numbers species is going to be rather less than that of a large population, but that's strictly speculation on my part; I've never had a class on evolutionary biology, or done much reading about the theory in that discipline.

 

If right, you could get rapid evolutionary change in such a species.

[Lawnmower Boy]

Re: Humans nearly went extinct

 

One wonders how much such an event influences later evolution. Could it have been pivotal in creating such an exceptional species as us?

 

 

We`re all above average!

On the other hand, maybe this just shows how narrow the ecological niche of early Homo Erectus actually was. There was a paper in Antiquity ...some time ago.. suggesting that the species started out as an opportunistic predator in Rift Valley volcanic chaotic terrain. Then we discovered fire (unless that happened hundreds of thousands of years later) and the world was ours!

 

 

 

Edit: just to be clear here, I mean to humorously reference German ambitions of world domination only in a kind and gentle WWI way.

[Kristopher]

Re: Humans nearly went extinct

 

There's at least one other suspected near-extinction event in the far less distant past, less than 100000 ybp, if I recall correctly.

[Matt the Bruins]

Re: Humans nearly went extinct

 

I've heard a much smaller number postulated for another bottleneck in Africa about 200,000 years ago, hence the "Mitochondrial Eve" whose descendants eventually supplanted the children of all her female contemporaries. I don't know how highly regarded the theory is, but it proposed a total Homo Sapiens Sapiens population that could have been as low as 4,500, with 1600 or so breeding individuals.

[Old Man]

Re: Humans nearly went extinct

 

Dammit! I was this close. I should have just tented the whole planet.

[Nyrath]

Re: Humans nearly went extinct

 

This is mentioned in Science Now for yesterday (19 Jan 2010). Statistics on the genetic variability in modern humans suggest that 1.2 million years ago the breeding population of humans worldwide bottomed out around 18' date='500 (an uncertain number, but certainly no larger than 26,000).[/quote']

And then, just before humans became extinct, a large black Monolith appeared before Moon-Watcher.

[RexMundi]

Re: Humans nearly went extinct

 

I think that attraction to Monoliths is why us guys go for that giant black 75" + HDTV.

 

~Rex

[Cancer]

Re: Humans nearly went extinct

 

Well, that and the big fridge with the glossy black finish. That the latter holds beer is a HUGE plus.

[RexMundi]

Re: Humans nearly went extinct

 

That's the True Monolith.

 

~Rex

[gewing]

Re: Humans nearly went extinct

 

Fodder for world-making....

 

This is mentioned in Science Now for yesterday (19 Jan 2010). Statistics on the genetic variability in modern humans suggest that 1.2 million years ago the breeding population of humans worldwide bottomed out around 18,500 (an uncertain number, but certainly no larger than 26,000). Humans now have a remarkably small genetic variability compared to other apes, and this is a signature of a species that barely eluded extinction in the evolutionarily not-too-distant past. That time is before modern humans (which arose 200,000 years ago); it's back in the Homo erectus era. There have been other suggestions that humans later went through near-extinction events, too.

 

For comparison, current world populations of the (endangered) species of chimpanzees and gorillas are about 21,000 and 25,000 respectively.

 

 

 

Interesting. I seem to recall reading somewhere a year or two ago that there is nearly as much genetic variation in Chimpanzees or Gorillas as there is between us and Chimpanzees???

 

Or am I misremembering and It was something about Pygmy Chimpanzees being almost as different from Chimpanzees as from us.

 

Damn, I'm tired, and some parts of my brain seem to be firing oddly...