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Humans Nearly Went Extinct 1.2M Years Ago
Hugh Pickens writes "Scientific American has a story on researchers from the University of Utah who have calculated that 1.2 million years ago, at a time when our ancestors Homo erectus, H. ergaster, and archaic H. sapiens were spreading through Africa, Europe, and Asia, there were probably only about 18,500 individuals capable of breeding in all these species together (PNAS paper here). Pre-humans were an endangered species with a smaller population than today's gorillas and chimpanzees. Researchers scanned two completely sequenced modern human genomes for a type of mobile element called Alu sequences, then compared the nucleotides in these old regions with the overall diversity in the two genomes to estimate differences in effective population size, and thus genetic diversity between modern and early humans. Human geneticist Lynn Jorde says that the diminished genetic diversity one million years ago suggests human ancestors experienced a catastrophic event at that time as devastating as the Toba super-volcano in Indonesia that triggered a nuclear winter and is thought to have nearly annihilated humans 70,000 years ago."
That's nothing. I mean, the whole race started from just two people, right?
this means that we're really all brothers and sisters, right?
Obviously this is when Adama and the fleet landed on Earth. BSG was right all along!
Check out my sci-fi book "Lacuna" at http://goo.gl/MVxX8
The end result is the same as that predicted for nuclear winter. Radiation is not the primary danger from a "real" nuclear winter, it's the smoke and soot that would spread through the atmosphere, drastically reducing the amount of sunlight received at the surface, killing plants and reducing temperatures everywhere. When a supervolcano goes off, the effects are nearly identical.
$_ = "wftedskaebjgdpjgidbsmnjgcdwatb"; tr/a-z/oh, turtleneck Phrase Jar!/; print
The 18500 people quoted is not the number of people capable of breeding, but the "effective population", an abstract measure of genetic diversity in a species. According to TFA, the effective population of modern humanity is about 10000, and the argument in the article is that this much lower diversity indicates that a lot of genetic material must have been lost in a near-extinction event.
(not trying to rain on your parade or anything)
Back on topic. Humans nearly went extinct during the nuclear missile crysis... In terms of survival requirements, we should have already sent a few groups to the moon and mars.
People enjoy watching disaster movies like 2012 (I saw it as a comedy myself), but they should realise that focusing all your resources (as a species) on "I want a TV in every room" is a losing strategy.
If I had the money, I would be long gone. "Yes, 21st century society is very advanced and we have everything we need, but if they have a power outage or similar in a hidden bunker in Russia, we all die".
new sig
I think this means we are a stubborn infestation, successfully resisting the Universe's attempts to exterminate us thus far. The Universe realized that we are harder to kill than cockroaches, and concluded that the only way to wipe us out is to place the means of our destruction in our own hands. Now, it's just a waiting game.
I prefer rogues to imbeciles because they sometimes take a rest.
Because 1.2 million is the same as 70,000, right? You must work for Goldman Sachs.
The effects might be similar, but the fact remains that they're different things. The end effect of a brain aneurism is also "nearly identical" to being shot in the head - you die due to loss of brain function. There's nothing "nuclear" about climatic changes brought about by volcanic activity. It's a thoughtless grasp for "gee-wiz" vocabulary, and thus bad journalism.
The DNA that creates different physical traits does mutate in (more or less) unpredictable leaps and bounds as time goes on. But that's not the DNA they look at in cases like this. There's long strings of junk DNA that does nothing at all - random leftover of mutations that didn't happen to affect our survival one way or the other. Because these don't affect physical traits, they aren't selected for or against and are subject to only one 'force', genetic drift. That's why they're fairly constant.
But why should we assume a uniform rate over time, when evolutionary theory says that genetic differentiation happens in leaps and bounds?
See, here is your problem, you're assuming evolutionary theory is correct to begin with.
Indeed, much of science is based on a giant leap of faith in linear regression; physicists, chemists, doctors, engineers, all use linear regression without questioning its assumptions.
No, they use linear regression and then test to prove it's a reasonable assumption.
What happened to those? Sounds like an excellent power source...
http://en.wikipedia.org/wiki/Geothermal_gradient
"The Earth's internal heat comes from a combination of residual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%)"
In a sense, those "green geothermal" power plants are really nuclear power plants.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
But why should we assume a uniform rate over time, when evolutionary theory says that genetic differentiation happens in leaps and bounds?
Sources should always be cited when making this kind of argument. I'll do it for you this time:
Pr. Charles Xavier, X-Men movie introduction speech
If this is a troll, it must be a kick-ass troll ...
I think parent poster should be getting insightful instead; talking about not trusting blindly; even if it is science ...
It's only with an open mind, more options can be found. Remember; there used to be science about the earth being flat ages ago.
"not trusting it blind, even if it is science", "open mind", "science used to be wrong" etc are expressions and phrases very heavily overused by creationists. He gives the game away by saying things like, "I used to be an Atheist", "science wants simple answers", "Science is as irrational as Wahhabism". It is very difficult to tell a troll from a true believer in Creationism. If Creationist walks like a duck and quacks like a duck, let us just call him a duck and be done with it.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
From The Onion:
Sumerians Look On In Confusion As God Creates World
"Members of the earth's earliest known civilization, the Sumerians, looked on in shock and confusion some 6,000 years ago as God, the Lord Almighty, created Heaven and Earth.
YIR numbers web 5
According to recently excavated clay tablets inscribed with cuneiform script, thousands of Sumerians--the first humans to establish systems of writing, agriculture, and government--were working on their sophisticated irrigation systems when the Father of All Creation reached down from the ether and blew the divine spirit of life into their thriving civilization.
"I do not understand," reads an ancient line of pictographs depicting the sun, the moon, water, and a Sumerian who appears to be scratching his head. "A booming voice is saying, 'Let there be light,' but there is already light. It is saying, 'Let the earth bring forth grass,' but I am already standing on grass."
-- Give me ambiguity or give me something else!
Oh no. We better get greenpeace on that to put a stop to that nuclear nonsense.
Camping on quad since 1996.
I don't expect them to use the term 'catastrophic clamactic event' in a flowing sentence.
Quite right. Such terms should be reserved for events like the 1912 San Francisco Shellfish Riots.
Linux, you magnificent bastard, I read the fucking manual!
The TWO (only two) genomes analyzed were from the subpopulation which left Africa. If you fully sequence a native south African more genomic variety, this hypothesis may not hold up.
"I do not understand," reads an ancient line of pictographs depicting the sun, the moon, water, and a Sumerian who appears to be scratching his head. "A booming voice is saying, 'Let there be light,' but there is already light. It is saying, 'Let the earth bring forth grass,' but I am already standing on grass."
So... an alternate headline would be "Ancient Sumerian on grass hears voice of God".
The enemies of Democracy are
But, the effect was spread on all H. Sapiens level species more or less equally, giving the more adaptable group the advantage of a sparse landscape. If the near-extinction event hadn't happened, H. Sapiens would likely have been out competed by entrenched specialists.
Bah, you call that news? Try:
"Humans Nearly Went Extinct 27 Years Ago"
the commander's Wikipedia entry says he:
You can follow any of the links in the above search, or here's a particularly lively read.