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Humans Nearly Went Extinct 70,000 Years Ago
Josh Fink brings us a CNN story discussing evidence found by researchers which indicates that humans came close to extinction roughly 70,000 years ago. A similar study by Stanford scientists suggests that droughts reduced the population to as few as 2,000 humans, who were scattered in small, isolated groups. Quoting:
"'This study illustrates the extraordinary power of genetics to reveal insights into some of the key events in our species' history,' said Spencer Wells, National Geographic Society explorer in residence. '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.'"
we will actually reach that population level again.
Environmental damage here we come!
Or perhaps instead of saying "I'm X race" just say "This is my speciality and these are my accomplishments!" Once you get to a certain average prosperity level worldwide, it eventually stops mattering.
Speaking as an American, as long as dumbasses think they're special because some of their ancestors came from Ireland 8 generations ago before proceeding to mix with every other background in the US, we're going to hear a lot more "I'm Irish" or worse "I'm 1/16 Cherokee, 1/2 Irish, 2/7 Italian..." crap.
Klingon programs don't timeshare, they battle for supremacy.
I have a whopping 10 mod points, but would rather participate in this discussion instead, so here goes:
:P
I think that this is actually plausible. Things to mull over that could make this an interesting topic:
1) What evidence, 70000 years later, would decisively display the difference between a flood and a drought?
2) Could the Noah story be an allegory written after the fact to describe this event, with only the details mixed up? If so, what does that tell us about this story?
3) What remnants of an Ark would one expect to find 70000, or even 5000 years after the fact? Conversely, what evidence could be shown that would decisively PROVE OR DISPROVE that the event happened? And I'm talking about scientific evidence here. Not anecdotal faith-based cruft. Not even science-based faith-based cruft, if you please...
Love these topics. Go people, go!!
Actually the study can't support the statement that there were only 2,000 of us at that time. What it does say is that only 2,000 of us alive at that time managed to pass down their genes until today. There might have been a larger population whose genes we have lost in the intervening time (e.g. during the Bubonic plague).
The problem with these studies is that there isn't any DNA record of the humans that didn't make it. The only evidence we could hope to find of the humans that have died out is fossilized remains, which are few and far between.
120 characters isn't enough to explain it.
And now we're an over-weight, not-too-bright, not-too-strong, disease-ridden, sorry-assed bunch of H. Sapiens.
What a difference 70,000 years makes!
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
Now that's the best concept I've ever heard on slashdot. Makes the internet really nice. Nobody knows what race you are, or education, or even sex. And none of it really matters in the end.
21st Century Renaissance Man
Also, keep in mind that the genetic evidence is just one line of evidence, and that's it's difficult to interpret. If their conclusions are correct, then other lines of evidence should corroborate their story. In particular, if humans nearly went extinct 70,000 years ago, then shouldn't we expect to see that in the archeological evidence, with stone tools becoming less common for a period?
This idea that we can prevent it, and then everything will be fine. Well there's two big problems with that:
1) What if even though we are the source, we can't stop it? What if it turns out there's just no way now to turn things around, we are too far down the road? What then?
2) Assuming historical extrapolations are right, the world has been much hotter and colder than it is now. Thus it is likely that will happen again. Thus no matter what we do, we are probably in for a big temperature change at some point.
So then if we assume it is true that a temperature shift of a few degrees will really screw us over, then we need to be preparing for it and figuring out how to deal with it. It really seems like a case of not if but when. Even if we are the cause and have the power to prevent this current change, a change that we can't will happen at some point. Also, just because we are the cause, doesn't mean we can prevent it.
Either way, the most sensible thing would seem to be to figure out what we need to do to be able to survive a temperature shift, not concern ourselves with what the cause is because unless we are extremely incorrect about past temperature, it is not a static function over any time period, and thus is not likely to remain so, regardless of what we do or don't do.
It bothers me that people keep talking about the hypothetical effects of global warming without any real data. CO2 levels have risen by 30%, and surface temperature have not shown enough of a trend that we can really say the temperature is even rising. Sure, there's less sea-ice than there was 30 years ago, but ocen levels have not risen.
Where's the beef? Why are people saying that we're going to see cataclysmic changes in our environment, when no appreciable changes have occured so far. What is the basis for all these predictions?
The most intelligent land animal almost went extinct, the second most intelligent land animal is an endangered species now, and a lot of the great apes are in trouble. Dolphins are doing OK, whales would be fine except for us, but neither is likely to develop technology.
Are we going to find life on other planets but discover that high intelligence is rare?
Because the inheritance graph of humans is a DAG flowing backward in time (thus cannot create cycles), with each individual having exactly two parents. These research results estimate the number of unique nodes of this graph at a specified point in time by essentially tracing backwards from who is alive today.
People don't "intermingle", they have children. If the children die, or all the children's children die (or all the children's children's children die, ad inifinitum), then your unique genetic code is erased (except the portion of your genetic code that you shared with other individuals who got it through a different path in the graph).
In fact, it's slightly more complicated than that because when you have children you only pass on (an essentially random) half of your genetic code. You might have the dumb luck that none of the unique mutations in your code gets passed on to your children because they never land in your children's 50%. You therefore might have had a unique mutation that cannot ever be detected in the future genetic record because by chance you passed on the "common" portion of your DNA code and not the unique mutation.
So yes, branches of this DAG can and do die off. Nothing "points" to them, so they die. In fact, this is the very mechanism by which natural selection and speciation occurs.
The arguments they use in the article are statistical and even though they account for many factors, in the end they can only work on information available from surviving DNA.
120 characters isn't enough to explain it.
Remember that the Bible was not written in modern english and that even in modern US sports world means the USA+Canada. What we read of a worldwide flood is unlikely to mean the entire planet in Sumerian (they had the flood story) or possibly an earlier language that wasn't written.
This study is based on Mitochondrial DNA, which is inherited through the female line. It's less than useful for determining the actual population, since the only population detectable through this technique is women who've not failed to have daughters. Note that my grandmother's mitochondrial DNA is going to be gone from the world after this generation, since she had only one daughter (plus two sons), that daughter had only two daughters (plus four sons), and those two daughters have only sons (two, last I counted). So, 60-odd descendents still living, but as far as this test is concerned, her entire family line is gone, or never was.
"I do not agree with what you say, but I will defend to the death your right to say it"
Clerk: Race?
Call me naive, but is this a question that is actually asked? In what situations? For what purpose?
I'm not from the US and do not know all your local customs, but I find the idea quite absurd (bordering on offensive).
May we live long and die out