A team of Genographic researchers and their collaborators have published the most extensive survey to date of African mitochondrial DNA (mtDNA). Over 600 complete mtDNA genomes from indigenous populations across the continent were analyzed…
Doron Behar said: “We see strong evidence of ancient population splits beginning as early as 150,000 years ago, probably giving rise to separate populations localized to Eastern and Southern Africa. It was only around 40,000 years ago that they became part of a single pan-African population, reunited after as much as 100,000 years apart.”
Recent paleoclimatological data suggests that Eastern Africa went through a series of massive droughts between 135,000-90,000 years ago. It is possible that this climatological shift contributed to the population splits. What is surprising is the length of time the populations were separate – as much as half of our entire history as a species…
Dr. Spencer Wells said: “This new study released today 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.”Paleontologist Meave Leakey added: “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.”
Our species survived an environmental threat of extinction when we were as scarce as 2,000 individuals. Now that we number in the billions, I hope we can keep from killing ourselves off – on our own.
Yep. Amazing stuff… really puts our tiny puny little lives in perspective…
Liked this one too:
http://tinyurl.com/7eby5
And if you correlate that to this:
http://en.wikipedia.org/wiki/Mitochondrial_Eve
Might well be that we’re all children of two peoples…
Wow, massive epic film could be made out of this… and with scientific backgroung, not like that smorgasbord that 10.000 was…
10.000 B.C.
sorry typo…
I wouldn’t use the word “evolution” to describe the separate development of different population groups. Evolution takes much longer than 100,00 or so years.
Keep in mind Humans share 98% of our genetic material with chimps. The actual variation between human beings (including skin color) is incredibly small.
The most common reason given for changes in skin color is mutation caused by solar radiation and other environmental conditions, as well as limited genetic diversity within the northern population groups.
White supremacists like to think that white skin is proof of evolutionary advancement. But really it’s just a minor genetic mutation.
Makes me wonder how long it might have taken, if ever, for chimps or apes to develop technological intelligence had humans gone extinct. And what that might mean for the possibilities of ET intelligence life.
RBG
And of course only physical features were affected by evolution. Any suggestion to the contrary is ridiculous and beyond the realm of scientific debate.
ben stein demands equal time for his asinine theories
“why humans turned white skinned”
We didn’t. We’re all brown skinned.
Some have more pigment than others,
as we moved North, there was less need for pigment.
Previous studies have shown that while human populations had been quite small prior to the Late Stone Age, perhaps numbering fewer than 2,000 around 70,000 years ago …
Damn!! Just 2,000 humans from a world without this extinction event. I guess that would be called “bad luck”.
If those 2,000 that probably just barely squeaked though simply hadn’t, millions of species would be a lot better off today. There’d still be saber toothed tigers, mammoths, woolly rhinos, giant sloth bears, moas and the eagles that ate them, passenger pigeons, ivory billed woodpeckers, dodos, Tasmanian marsupial “wolves”, and many many others.
Damn Homo Sapiens ruin everything!
#4 – chuck,
I wouldn’t use the word “evolution” to describe the separate development of different population groups. Evolution takes much longer than 100,00 or so years.
Perhaps, but certainly not always.
Rapid island-lizard evolution
I think this is beyond what even the most ardent advocate of punctuated equilibrium would have predicted.
#6–Mike==I sense you are being very clever, but must admit, I miss the point you are trying to make.
Yes, everything in the world, including human evolution, is physical.
Self-awareness reamins a mystery but is also part and parcel of the physical.
Maybe I’ll get a laugh if you explain it once more?
#6 – MikeN,
Just remember, the brain is a physical feature too. A hardware upgrade gives your computer capability to accept more complex program and still complete the task in the required time.
Perhaps the same is true of a brain. Let me go ask a sperm whale (brain weight: 20 lbs), maybe s/he will be able to answer. Be right back.
What really strikes me is just how much sense this makes. Think about it, 70,000 years ago a dramatic event reduces the human race to a few thousand survivors. But of those survivors only those that descended from one woman survived – hence ‘Mitochondrial Eve’. Now it’s a pretty good bet she wasn’t the only female to survive. What is a certainty is that her offspring had to be some very competitive and muderous individuals, and to think we all are the descendents of this one woman…
#13 – amodedoma,
Just to avoid sexism, we should not rule out the possibility that she was also a murderous individual. Otherwise, really excellent point. I hadn’t thought of that.
#14–Scott==murderous????
Or just the opposite? I can make a “logic” argument for both.
Any facts?
Or just being Misanthropic (in a very anthropic way?)
No no no, it’s just that when numbers fall to such low levels (couple of thousand individuals) it’s easy to branches “dry out” in some generations. Some females had offspring for some generations, but those families extinguished. And remember, mitochondrial DNA traces DNA replicating only via mother side. If some of these females had only male offspring, their mitochondrial DNA would be extinct.
What really has been said is that we all come from the same (mitochondrial Eve) mother, but only on the mother side.
OTOH Genetics also tracked down our ancestral “Adam”, via the Y chromosome.
#14 – bobbo,
Just being misanthropic. Actually, in this case, I was just furthering a misanthropic thread that was started by amodedoma.
#17–Scott==well I was going to give you a snappy statistical analysis that make “Eve” a virtual certainty but joaoPT at #16 stole my thunder. He is exactly correct.
#16 – joaoPT – Not trying to say anything bad about women, I worship them. Instead of using the term murderous I should have just said aggressive, I was exagerrating for dramatic impact. The fact that the mitochondrial source narrowed in one generation or a hundred doesn’t change the fact that her descendents were more likely to survive and reproduce. Or they were grossly superior(unlikely) or had some very agressive attitudes towards ‘outsiders’, it’s impossible to say for sure. However if we examine human nature as it is now I would bet on these guys eating their neighbours for lunch.
Just wrap up, and forgive me the pun, all women come from the same mother and all men come from the same father.
This is a new angle on the “women are from Venus, men from Mars” stereotype.
19-amodedoma.
Nobody will follow this, but…just struck me.
We’re talking women here. Maybe aggressiveness didn’t had a part in it. Maybe other earthly advantages played their role. Remember we’re talking mitochondrial DNA from mother to daughter. Maybe our common mother was beautiful beyond belief for the time, and her daughters too. Maybe they were the prized catch of the finest warriors.
…
Man, earlier on I talked about the fantastic Epic this tale would be. And it gets juicier and juicier as I think of it.
10 M. Scott Re Humans responsible for extinctions.
90% of all the species we know about are extinct. The Paleobiology Database lists 120,641 described taxa, and most of these are Genera to say nothing of the 100 million + species all this encompasses. These are but the slightest of shadow of the number of species that once actually existed through the eons.
I don’t have a handy guide as to how many of those extinctions were caused by one species out-competing another but you can bet it is significant. Death is the engine that powers evolution.
So though animals have been ripping apart and eating other living animals for much longer than 65 million years (as per their evolved DNA programming & reflecting the sublime beauty of nature), isn’t it gratifying to know that the “more evolved” humans among us are above that sort of thing?
Now, I’m sorry, I’m about to get up onto my soap box because… isn’t it really high time those same enlightened humans – guided by the strong leadership of PETA – finally does something about the savage and pathetic “cold-blooded” killings between animals within our political jurisdictions? Think terrorized little deer and baby seals getting their throats torn out while alive by predators. No, I’m sorry, we have to take a stand, and it all must now stop.
If we can be upset about any cruel treatment of our pets and food animals, then we should equally be upset about the obvious cruelty that exists day & night in our forests and oceans. The animals don’t know the difference between “good” politically acceptable cruelty in the wild, and “bad” cruelty by people! Suffering is suffering is all they know.
If we can attempt to force thousand year old stubborn cultures like Saudi Arabia to suddenly embrace our more enlightened Western ideals, why shouldn’t we also impose our standards upon all life that is so clearly within our responsible stewardship?
Even if stopping all this vicious animal bloodshed turns out to be more challenging than expected to enforce, I still believe we should at least take a stand and organize protests as an expression of the solidarity of our ethics on this matter.
We create impractical policies reflecting our principles all the time. If good people have the insight, will and political savvy to create “nuclear-free” cities, we can also create “Animal Savagery-free” countries.
RBG
#22–RBG==good post. Rhapsodic almost. Scott enjoys displaying his nickname as far as he can push it. My own emphasis is one that Scott agrees with and that is that as we exercise our dominion over the animals, the problem is we are killing off species that will ultimately result in our own demise. We simply don’t understand the living web we remain a part of.
You touched on it but lost it. The key is we are stewards, and animals don’t have a choice.
But we do. Scott and I depart here–I think the choices should be made to maximize human culture, and Scott wants to favor the animals. In the end, we may be closer together than that characterization may indicate.
RBG,
Get off your soapbox. Your numbers are likely correct for past species extinction. They may even be higher. However, our current extinction rate is over 1,000 times the normal background rate of extinction. We have already caused a mass extinction greater than the one that took out the non-avian dinosaurs 65.3 MYA.
Don’t cut humans short.
We’ve earned our rightful place in the history of this planet as the cause of the sixth great extinction.
We are a catastrophe.
The only thing left to think about now is how bad this extinction will become. Will it be only as bad as the extinction of the non-avian dinosaurs?
Or, will we cause severe and runaway global warming at the same level that cause the Permian Triassic extinction event 250 MYA, the current record holder for worst extinction ever, and also caused by global warming, though obviously not human caused?
This is not a PETA issue. It’s not about killing individual animals. I eat meat. So, I’m no angel here. The difference is the willful destruction of habitat that is causing whole species to go extinct at the rate of one per hour. While you were reading this blog, another one died.
So how did that last big global extinction work out? The mass extinction of 160 million years of the dinosaurs almost certainly paved the way for the rodent-like animal that evolved into man. Evolution’s version of the high colonic was a good thing.
So by my calculation, the next big extinction ought to produce the Arthur C. Clarke’s evolutionary Star Child.
RBG
RBG,
Get the dates right. Non-avian dinosaurs went extinct 65.3 million years ago. The biggest extinction was 250 million years ago. The former was caused by a cometary impact. The latter was caused by … brace yourself … global warming. Of course it was not human caused. If we go that route, yes, it may open many doors for other species. However, those doors may not open for ten million years or more.
Are we willing to play games with time frames like that?
Can we call ourselves a moral species if we do?
Some might argue that the extreme improbability of this indicates intelligent design.
Not that I would argue that. I’m just saying…
#27 – Greg Allen,
Yes. Some might make that argument. However, they’d be flat dead wrong. Even if something were to disprove evolution actively, as opposed to arguing by probabilities and statistics when evidence is required instead, it would not add weight to ID.
ID is quite simply a failed hypothesis. In order to explain complexity, we must first postulate complexity. Or, in order to explain intelligence we first postulate intelligence. Or, whatever. It flies up its own asshole in infinite recursion.
If intelligence was required to create (blah) then intelligence was required to create the intelligence that created (blah). And, intelligence was required to create the intelligence that created the intelligence that created (blah).
It’s turtles all the way down.
And how is it you know that the current species extinction rate is faster? That more species are observed now which have gone extinct than what we can find in the fossil record?
>>If intelligence was required to create
>>(blah) then intelligence was required to
>>create the intelligence that created (blah).
Ah, Scottie, you’re so militant. As all we believers know, God is the ultimate intelligence, and nothing was required to “create” him/her. As it was in the beginning, is now, and ever shall be, world without end. Amen.
As to people who deny evolution, pfffft. There’s a dipshit fucktard born every minute, or whatever it was that PT Barnum said.
26. Scott.
I didn’t provide any dates, only the span of time dinosaurs dominated the Earth.
http://en.wikipedia.org/wiki/Dinosaur
yes, it may open many doors for other species. However, those doors may not open for ten million years or more.
It’s short term gain that has caused the threat of Global Warming. (That’s the best I can do.)
RBG
#30 – MM,
Ah, Scottie, you’re so militant. As all we believers know, God is the ultimate intelligence, and nothing was required to “create” him/her. As it was in the beginning, is now, and ever shall be, world without end. Amen.
And yet, you can’t just apply that logic to the quantum state of the universe before the big bang?
Further, you seem unwilling to explore the origins of god. Since you believe in one, I would think you’d want to know more about him/her/it. Why is it that only nontheists feel comfortable asking about the origins of god?
Wouldn’t it be a way to grow closer to your creator to ask questions and investigate?
BTW, why god? Why not turtles? Why not FSM? Why not many gods? Ganesh is so cute!! And, then there’s always Thor; if I can’t see Thor, at least I can hear him.
How do you choose which one? And how do you choose that there is only one?
And, again, by continuing this thread, we both prove to be equally militant. So, you can stop trying to be holier than thou. You’re not. And, you can stop claiming to not be proselytizing. You are. As assuredly as I am opposing religion, you are trying to spread it. You do an excellent job of convincing yourself that this is not true. But, it is.