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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?
Luckily, magic underwear was discovered and humans survived the event.
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
There should be some sort of correlation in the results.
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
Humans Nearly Went Extinct 70,000 Years Ago
If someone says he and his monkey have nothing to hide, they almost certainly do.
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.
What happened to those? Sounds like an excellent power source...
I'm just saying, there's some suspicious congruencies there.
No kidding!!! What do you say at this point?
More evidence supporting the B Ark theory of human origins...
It is based on a faith that DNA mutates at a uniform rate over time.
Actually one would expect DNA conservation to indicate kinship regardless of the mutation rate.
No kidding!!! What do you say at this point?
Aight, Bloodninja was his name!
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.
You can't have circular logic with out logic to begin the circle. I'd suggest picking a place to start then figure out if where you started is the right place.
Sounds like where we'll be at after another three seasons of American Idol.
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.
I'm getting my PhD in statistics, and I've taken several courses in genetics -- enough to know that all theories in genetics are wrong. ... I used to be an atheist, but I've come to the conclusion that science is just as irrational as Wahabbism. ... Science wants simple explanations, yet the world isn't simple; it is inherently an exercise in circular logic.
You sound like that idiot (Jonathan Wells?) sponsored by Reverend Moon to get a Ph D in biology so that he can destroy the Theory of Evolution from inside.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
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.
The Ancients died of a plague and most of them ascended.
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
You sound like a crackpot in training.
Everybody in the field knows that DNA mutation rates need not be uniform, so the alleged 'faith' only exists in your imagination.
Furthermore ascribing random claims to evolutionary theory and pretending to have been an atheist is characteristic for the dumber religiously inspired anti-evolutionist pamphlets.
I wonder why you felt the need to post this rubbish when you clearly can be smarter than this.
Or did you just leave your terminal unattended?
The humans had a huge mineshaft gap over the neanderthals, and were smart enough to keep 10 women for every one man in their mines!
Ok so they find that humans are genetically homogeneous compared to other species. But how do other species develop diversity? One way is to have isolated populations. If we imagine that humans were different from chimps and other primates in that humans travelled far and wide, there would be no isolated groups of humans, the whole of central africa would be effectively one gene pool. That alone could make humans less genetically diverse than other primates, without invoking any theory of a near-extinction.
http://en.wikipedia.org/wiki/Yellowstone_Caldera
ah yes, i've heard of mexicans and canadians, there's only a few in the world, but they're real. as for these so-called "americans", i believe this is a mythical nationality, i don't think they ever really existed. they're just bogeymen made up to scare small children
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
The proper description would be volcanic winter.
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.
--- I am known for the ones who want to find me on the net. Is that a privacy risk or a privilege? One might wonder..
Science seeks to explain, ie. to make complex things plain and amenable to human understanding, which is by definition a reductionistic activity. That's hardly a new insight. Your attempt to blame science for the simplicity of its explanations betrays a fundamental misunderstanding of what science can do. Science that is so impressed by "complexity" that it shrinks back from it is obscurantism.
Oh yes - "I used to be an atheist" is a complete non-sequitur in my opinion, especially if the opinions that accompany the statement are an embarrassment to any reasonable theory of science. Get your PhD in statistics if you like. But if your genetics courses were so bad, what makes you so sure that your stats curriculum isn't equally flawed? And have you ever actually talked with your engineering friends? I happen to be an engineer, and have used linear regression, being painfully aware of its assumptions and limitations. There's absolutely no "leap of faith" here. It's acquiring a mental toolset and learning how to use it appropriately.
"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."
Yet, as we're discovering, "junk" DNA is really a misnomer. Every year, we discover more and more ways in which the supposedly inactive junk DNA actually perform important biological functions. It could also be that selection pressures for a given piece of DNA existed during certain time periods and not others; there is no reason to assume a uniform selection pressure (or lack of pressure) over time. The models in use today assume Hardy-Weinberg equilibrium, which is never observed in the real world, but is somehow assumed to work over millions of years. The theories are non-testable, non-reproducible, and non-falsifiable. In short, it makes dogmatic assertions no better than religious texts.
So this is the obvious solution to anthropogenic global warming, isn't it? And it'll use up those hard to maintain, easy to steal, weapon stockpiles. What are we waiting for?
On y va, qui mal y pense!
The advent of Karaoke!
Invenio via vel creo
While I agree that it's a totally inaccurate term (unless the disaster were a criticality event of an underground uranium reservoir, or similar) it's also the simplest way to get accross to a non-technical public the intended image. I don't expect them to use the term 'catastrophic clamactic event' in a flowing sentence. A better phrasing would have been "nucler winter-like disaster" or "a 'nuclear' winter", though.
Write your representatives! Repeal the 2nd Law of Thermodynamics!
...thought at first that the headline was "Humans Went Extinct Nearly 1.2M Years Ago" and thought, "Boy, we're doing pretty well for an extinct species..."
Good news! We should soon be able to prove to everyone that you are correct. From the Wikipedia article on the Yellowstone Caldera, "The three super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago". If the trend continues, the next eruption is about due.
My webcomic
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!
Genetics today is obsessed with conserved DNA sequences as "proof" of evolutionary kinship. It is based on a faith that DNA mutates at a uniform rate over time. But why should we assume a uniform rate over time, when evolutionary theory says that genetic differentiation happens in leaps and bounds?
Science fail. DNA does mutate uniformly. Genetic differentiation based on the mutations goes in leaps in bounds because of selection pressures that drive evolution,
I mean, don't we already know that our species went through several bottlenecks? If I remember correctly, at one point we went through a bottleneck so small that the total number of breeding females was in the double digits. What I am more concerned about is when the next bottleneck is going to happen, and what will be the cause of it.
The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
Yet, as we're discovering, "junk" DNA is really a misnomer.
It was never meant to denote that it did nothing, just that we hadn't discovered its function yet, so it got put aside for the moment.
I'm looking forward to your articles on this subject in scientific journals.
Bert
Back then, I'm assuming survival from a cataclysm had a lot to do with being at the right place at the right time, and you only had to fight for scarce resources with the people nearby. If a cataclysm happened today, it would be easier for people to escape to the remaining habitable areas, and we have a lot more tools to use to fight over those scarce resources. If we ever have a nuclear apocalypse, I bet it will be due to a sudden world war triggered by a natural disaster.
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Well, assuming half is male, you can "only" bang 5k women.
Personally, I wonder if this might be the psychological root-event of the persistent and widespread human eschatological theme of 'world destruction by fire' etc. One might even see a parallel event in the Christian Bible's expulsion of Adam and Eve from the Garden of Eden - prevented from returning by "...a flaming sword which turned every way..." (KJV).
It seems that since Troy, we're finding that all the great myths and legends that have come down to us through the ages seem to have some kernel of truth at the core, overlaid by 00's if not 000's of generations of encrustations of ignorance, superstition, and the (apparent) human compulsion to make a sensible story out of the chaotic universe.
-Styopa
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 flood story is most likely a composite of semi-historical and mythological events surrounding the flooding of the Tigris and Euphrates rivers. It may also be related to the flooding of the Persian Gulf at the end of the last glacial period, when trillions of gallons of sea water flooded into what was a very large (and possibly very fertile) valley. Since the destruction caused by this event, and the resulting 10,000 years of salt-water erosion, would've wiped out any sign of an ancient hunter-gatherer or subsistence civilization in what is now the Persian Gulf, it's impossible to prove. But it's still fun to speculate.
God invented whiskey so the Irish would not rule the world.
That last season of SG1 was really hard to watch. And Daniel ascending was really stupid also.
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 am no religious fanatic. I will continue to work in science. I accept that I will become a priest of yet another religion called "science"; it is no different from tasks that religious priests performed in the past, when they did work we would consider science, math, or botany. Our lives today are no less ruled by faith than in times past; we merely place the faith in a secular materialist view of the world. Today, we live in a world governed by materialist extremism.
If you call science a religion of materialism, you're clearly missing the point.
Even before the modern era, man had spread throughout the planet save Antarctica. Mountains, prairies, woodlands, sea coast, jungle, desert, arctic, we were there. I can't think of a another land species (apart from microorganisms) that was so wide spread.
This suggests that mankind is spectacularly adaptive in comparison to other species.
Alternate explanation, it IS nuclear, but because
- In the future we invent time deflectors: you attack us with nuclear warheads, we deflect them to the past
- Atlantis legend was true, and they managed to get nuclear power and blow their entire civilization
- Star Trek XXV, plan to eradicate the new Kirk in particular and Federation in general killing all human predecessors a millon years ago
- LHC (still should be more probable than it open a hole thru time and makes a nuclear winter back then than creating now a earth swallowing black hole)
- AVP, low tech (nuclear) version, Is cleaner to play it in some primitive and yet unhabited planet.
From TFA:
Um. What?
So, according to the research, 1 million years ago the human population was about 55,000 with a genetic diversity 2-3 times greater than that of modern humans. Can someone help me understand how they get to a near extinction conclusion? Is it just that the population is lower than expected? TFA is not very clear on the point...
In the land of the blind, the one eyed man still has no depth perception.
"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
Humans Nearly Went Extinct 1.2M Years Ago
So, Microsoft, RIAA, MPAA, and software patents existed back then also?
If Pandora's box is destined to be opened, *I* want to be the one to open it.
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.
"If you call science a religion of materialism, you're clearly missing the point."
As far as I have heard, science experiments are performed on physical objects, then replicated by other laboratories before the theory is accepted further. This sounds like materialism to me.
Granted, one could argue that fields such as mathematics or cosmology do not perform physical experiments; they make pseudo-theistic conjectures on the universality of their results. The conjectures are debated by panels of authorities in the topic, then eventually accepted as "theorems", "theories", or "laws". The physical or mathematical laws are assumed to be the same everywhere in the universe, unless experimental data from the "lower" sciences prove otherwise, e.g. the Voyager spacecraft travelling faster than expected outside the solar system. Then scientists propose an "anti-gravity constant" and place their faith in the new "universal" result.
I put on my robe and wizard hat.
Lock the wife and the dog in the boot of the car.
Return one hour later.
Who's happy to see you?
so the alleged 'faith' only exists in your imagination.
Isn't that pretty much always the case? Someone who doesn't like (a specific field or conclusion of) science will claim that the science itself is based entirely on untested assumptions and is thus equivalent to faith or "dogma", and the claimant will never have bothered to find out what actual assumptions are being made and what testing has been done to verify the hypothesis. It is, itself, a claim based entirely on a pre-existing belief that the science must be wrong.
The ironing is deciduous.
The enemies of Democracy are
There is an XKCD for everything. Here is yours.
http://www.xkcd.com/675/
There is a war going on for your mind.
Actually, your post helps to point out the primary point of TFA. There really is no intelligent life on earth. It died off before it could mature.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
In that event, I would not rule out the chance to preserve a nucleus of human specimens. It would be quite easy at the bottom of some of our deeper mine shafts.
Mr. President, we cannot allow a mineshaft gap!
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
Have you heard of the Black Sea Deluge Theory?, basically, they found ruins at the BOTTOM of the Black Sea. Combined with geological records, many speculate that there was a single, massive Flood in the area that wiped out entire cities. This could be the basis for Noah's flood.
Of course, when the range between eruptions is 660K to 800K, the low end of that would still make it another 20K years before the next eruption, or roughly twice the entire length of the history of human civilization. "About due" in geological time is very different from most people's view of "about due".
Yes, I'm aware the eruption could come earlier than previously observed, but it's not really worth worrying about events with astronomical odds that you can do nothing about now is it?
$_ = "wftedskaebjgdpjgidbsmnjgcdwatb"; tr/a-z/oh, turtleneck Phrase Jar!/; print
Or they could have just said 'volcanic winter' like the Wikipedia page they link to.
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.
Now, now. That was a perfectly cromulent use of the word in that circumstance.
Space game using normal deck of cards: http://BattleCards.org
I'm sure there's a Daniel Jackson joke in there somewhere...
Finally, somebody's come up with a quick fix to global warming!
"If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
...
There is nothing wrong with genetic theory.
Minor events at a molecular level occur at a fairly static rate. This does not conflict with the stuttering macro-evolutionary model, since the probability of any random change having any effect is low, and given that there is such an effect, the probability that it is positive approaches zero. The "rapid" evolution people look at is the very rare occurrence of an extremely beneficial trait, or (more likely) the very rapid changing of selective pressures.
In the case of an extremely beneficial trait, the ability of a creature to propagate the change (and out compete genetic rivals) explains the limited number generations required for near complete saturation of a population with the trait.
In the case of a rapid change in selective pressure, traits which were once unimportant (and therefore partially present in a population) can suddenly become extremely beneficial or extremely detrimental.
One such example of rapid change in selective pressure can be seen in the Peppered moth, which evolved to be much darker when the industrial revolution of England coated trees with soot. http://en.wikipedia.org/wiki/Peppered_moth_evolution
Not really, no. Consider that for protein encoding, there's a mapping of 64 codon combinations to create any of the standard 20 amino acids (and a few stop codons). Ie, if there was a specific protein that there was a selective pressure for and the gene to produce that protein was 20 codons long*, there'd be ~4.85 million possible genes that could exist to create that protein. Now, presumably this is the case because selective pressures have selected our first ancestor as the right balance of protecting against destructive mutation and there being enough phenetic change that selective pressures will actually leave an organism alive after the environment changes. So, one would also presume that the junk areas of DNA also have a certain level of resiliency to mutation (ie, that there's probably a many to few mapping for whatever function they have, although the exact ratio is probably not the same ~3:1 as gene/protein mapping).
In short, even presuming there were a joint selective pressure and that there was something equivalent to "one true path" to the necessary result, the actual encoding is unlikely to be identical in multiple species, regardless.
*Throw in a stop codon, and the actual gene could be much longer and have a lot of junk codons. And this doesn't even get into weird things like badly formed nucleotides in DNA.
Eurohacker European paranoia, gun rights, and h
non-human animals have humor. they play jokes on each other in nature and sometimes laugh. this is not intended to be a funny comment.
No, maybe you should learn to read and pick up a science book.
Yes, I'm aware the eruption could come earlier than previously observed, but it's not really worth worrying about events with astronomical odds that you can do nothing about now is it?
Is this in a memo? Could you send it to the airline industry? Thanks.
After reading this one, I've read about super-volcanoes on wikipiedia, and it says those eruption lower earth's temperature and can trigger a small ice age.
Maybe an eruption like that could save us from global warming?
It's a little bit scary anyway...
Well, in the last double-episode of TNG, "All Good Things", there is a space-time anomaly which threatens to stop the first formation of the seeds of life on a nascent Earth. Way before there were any human predecessors...
I never said there was anything wrong with genetic theory. The OP was making a point about scientific assumptions being bunk, however to prove one his points he bases it on the validity of a scientific theory.
Ironic.
First of all, we know that certain types of DNA do mutate at roughly linear rates because the biochemistry shows that they should. SNPs in long-stretches of non-coding DNA for example must work this way. Moreover, if our basic models of mutation were wrong we wouldn't see data that makes sense: we'd see a lot of gibberish when we tried to work out relationships by age. Moreover, the vast majority of evolutionary relationships worked out using DNA comparison aren't making statements about the time periods, merely woking out relative trees, which works out even if your mutation rates are changing drastically. You still get a nested hierarchy. I'm deeply worried by your claim that you are getting a PhD in statistics.
Utterly wrong. In fact, it completely misses the point. In fact the primary way we detect whether any junk DNA is functional is by seeing whether it has been strongly conserved. Use of genetic material to date in this fashion uses DNA that isn't being subject to selective pressure, i.e. doesn't have any function. And these hypotheses are easily falsifiable. For example, there have been studies where they have knocked out large portions of the mice junk DNA and see no effect. Even if scientists were using extremely naive approaches of the sort you think they are (which they aren't) they'd still be far better than "dogmatic assertions" from "religious texts." They'd then be imperfect and would require better modeling, but there's no way to engage in better modeling of the Koran or the Bible. So your comparison is idiotic even if we granted you your incorrect assumptions about how mutations and junk DNA are modeled.
Others have speculated that a megatsunami - possibly caused by the collapse of a volcanic island during an eruption or even a meteorite / comet strike - could have been the origin of the flood myth. It's interesting to note that many civilizations around that part of the world apparently shared the myth of a great flood.
I suppose it's also possible there were several different flood events that got melded into one great flood myth.
This is so wrong I'm not sure where to start. Suppose that non-material entities existed (whatever that would mean), say ghosts, Scientists would then be able to study their properties and analyze them just as they do "material" objects. Science makes no assumption other that anything in the world is "material." Now, an argument can be made that science assumes some form of naturalism, in the sense that the universe obeys regular laws. However, even then, one needs to make a distinction. Philosophical naturalism is the claim that the universe acts under naturalistic laws. Methodological naturalism is just acting like that is the case for methodological purposes. Science requires the second, not the first. At a philosophical level, one has a lot of trouble explaining why methodological naturalism works so well without assuming philosophical naturalism but science doesn't care about that issue.
Your comparison to Voyager is also poorly thought out. Yes, science isn't perfect. That's ok. All theories are inherently tentative. There's no proof in science. That's ok. We use a theory or hypothesis until a better one comes along. As we do that, we asymptotically approach a good understanding of the universe. However, you can't say because we don't reach that ever that somehow there's a faith assumption. Newton's law of gravity and associated work was a clear improvement over Aristotelian physics even though Newton was then replaced by a better approximation by Einstein. Indeed, we knew long before issues with Voyager that general relativity would one day need to be replaced by something else. But your example of Voyager is particularly bad (among other problems the only clear anomaly is in the Pioneeer probes, not Voyager). Moreover, the response of scientists was the exact opposite of what happens with religious dogma. When religions encounter something that wrecks their religious beliefs they don't almost ever go "hey! That's really cool. Let's figure out why we were wrong." But that's precisely what scientists do when they find out things that don't fit what they know.
Your confusion is further indicated by putting math in with the various sciences. Math is not a science but is its own branch of learning (it doesn't make falsifiable claims and has a minimal chance at making actual truth claims of the form "given a system satisfying axiomiatic set X, the following must hold"). Theorems in that regard aren't at all like physical theories. Humans might have trouble with that for sociological reasons (since humans make mistakes) but that's a completely separate issue.
An equally valid hypothesis is that there was no environmental change, but that in an otherwise genetically diverse population one small group gained a genetic competitive advantage over other proto-humans and began to multiply wildly, killing off or starving out the rest of the gene pool. It would be interesting to compare the age of the various genes for cognitive ability, speech and socialization to see if any date to the period where these choke points occurred.
I would like to think it was a gene that supported empathy or cooperation that enabled them to out-compete their neighbors, but rather I suspect that a genetic disposition to xenophobia is a more likely culprit...
"I love his boyish charm, but I hate his childishness" - Leela
Guys, we have to prevent Sephiroth from summoning Meteor or we'll all be wiped out again.
I don't doubt the research at all. It is saying that there was a relative lack of diversity of generic material at a certain point. I just have some questions about their conclusions.
We already have lots of models of societal structures where a relative few individuals are providing all the population, from bees and meerkats to elk. The best we can say is that a relative few individuals were mating and procreating.
Best regards.
Considering the massive percentage of the world's population that lives withing 100 miles of a coastline or major river, this isn't a surprise. Historically civilizations developed along the major rivers -- Tigres-Euphrates, Nile, Amazon, Yellow, Indus, etc. so every major civ having a flood myth isn't far fetched at all.
Learning HOW to think is more important than learning WHAT to think.
Let's say the population of inter-breedable humans went continuously up so population rose every year. In this case you could still have genetics that indicated "near extinctions." That's because some families died out even as other families were thriving. So even though the population never went down, it'd still look like we were down to just a few couples (my gosh, we were nearly extinct!) since only their descendants made it all the way through.
This implies that had those families not survived, some others would have and it would still seem like we were on the brink (a different brink perhaps) of extinction. That is to say, WE WERE NEVER IN DANGER OF EXTINCTION.
that long ago, we would have never had an Apple Tablet on January 27th. What a scary thought!
Not technically at the bottom, but more like at roughly 300 feet (100 m) of water off the Black Sea coast of modern Turkey. By looking at this picture, http://en.wikipedia.org/wiki/File:Black-sea-hist.png, it is perfectly deductible to assume the boundries of the Black Sea were different back then and normal for folks to build stuff on the coast.
Tired of my customary (Score:1)
Why is that a problem? Floods happen. Occasionally an extremely large one happens. It's impossible the check the flood myths to detect that they happened at the same time, so the most reasonable theory is that they didn't.
"I was up on top of this large hill, and there was water as far as I could see" may well have been the original story. Each transmission to the next generation "improved" the story. Ever played telephone?
I think we've pushed this "anyone can grow up to be president" thing too far.
Good news! We should soon be able to prove to everyone that you are correct. From the Wikipedia article on the Yellowstone Caldera, "The three super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago". If the trend continues, the next eruption is about due.
Yes, 640k years should be enough for anyone.
The Tao of math: The numbers you can count are not the real numbers.
"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, "
Is there anybody here in the know about ALUs?
I can live with 18.500 individuals, it makes some large strides in the evolution of the brain more likely.
But I can also imagine that we do not know about extinct ALUs. Sat there were more people genetically more prone to jump of cliffs, and this was linked to some different ALU which was missed in this survey due to rareness or extinction, then there could have been a larger worldwide population than this calculation suggests,
Damn you, I actually tried looking those up.
...
Low genetic diversity world wide, among three different species of great ape, when there had previously been great genetic diversity is indicative of catastrophe.
After all, I am strangely colored.
An equally valid hypothesis is that there was no environmental change, but that in an otherwise genetically diverse population one small group gained a genetic competitive advantage over other proto-humans and began to multiply wildly, killing off or starving out the rest of the gene pool
World wide? That's not an equally valid hypothesis.
After all, I am strangely colored.
Interestingly, the story Noah is not the only recording of a flood during that time period. In fact almost every ancient society stretching from Africa to the middle-east, to India and down around into Malasia has a mythology of a great flood and all of these mythologies date back to a similar time period.
Some scientists figured this couldn't be accidental and used the geography as a clue for a search. What they found was what appears to be a fairly sizeable impact crater off the coast of Madagascar dating back to roughly the same time period. In theory this would have cause a tidal wave hitting all of those geographical regions.
http://www.nytimes.com/2006/11/14/science/14WAVE.html
Besides, there was the other near extinction 70K years ago. Wht I find interesting is the near extinctions were probably what led to modern humans' intelligence and other traits (like humor) that makes us so different from other species.
This is not a bad hypothesis. Large populations tend to undergo strong purifying selection (selection for the "normal" of a trait and against the extremes). Because of this, any new traits that appear in a large population by random mutation have a good chance of "getting lost in the noise" so to speak. They have a smaller chance of becoming fixed in the population.
However, if you weaken the purifying selection (the two easiest ways of doing this are reducing the population through a bottleneck or by the founder effect of a small population immigrating into a new ecosystem) new traits have a better chance of getting fixed and propagating in the resulting population(s). Human populations have gone through bottlenecks and come out with new abilities on the other side, so the possibility that such a situation is what gave rise to human level intelligence is a good one.
Weakened purifying selection is the main cause of increased genome complexity and the arise of new adaptations, more powerful and "sudden" than gradual change by natural selection. Sometimes a population has to do very badly in order to have a chance to gain the adaptations necessary for survival.
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
While the few thousand left faced extinction, they all simultaneously realized it and said 'lets build a spear and a roof.' Ah, the birth of technology.
We're actually descended from Minerva's lunar colony, you know.
I have a book that shows the most holy being; who although he is everywhere, must be searched for by each reader.
All hail Waldo!
It was, and Jesus was a Jew, too.
The Christians think that by binding two separate book together, makes them all one 'book.'
Of course in Deuteronomy - the last book of the Torah (12:32) - it says that you: shouldn't add anything to this work or remove anything from it.
Of course slash-dotters know perfectly well what the bible was: it was humanity's first hard drive! Think about it... a fairly random collection of things we decided to save for latter like: family records (begat, begat begat), recipes (there's one for honey cakes I found once), prOn (Song of Solomon), cool battle stories, song lyrics, practical survival advice...
It's interesting you use the word 'faith'. "...It is based on a faith that DNA mutates at a uniform rate over time..."
You see - science - and more specifically DNA mutation rates - aren't based on 'faith' at all.
'Faith' is what people use to believe in things like: "If I have 'faith' in a magical corpse-on-a stick; I will live forever!!!"
That is why - if you travel the world - people have 'faith' in all kinds of different things - and think everyone elses 'faith' is wrong.
Science is based on rigorous, repeatable testing of the physical world; which is why scientists and engineers and doctors and mathematicians all pretty much believe the same things, and a medicine that works in Iceland, works just as well in Jakarta. And a plane that can fly over Mexico, can also fly over Dubai.
"...evolutionary theory says that genetic differentiation happens in leaps and bounds..."
No, it doesn't. Evolutionary theory says that genetic change is a fairly slow, fractional process; you're fairly similar to your parents, who are similar to their parents and so on... going back millions of years. Only people who believe the biblical creation fable think that people were created in a single leap and bound - i.e. one day.
....would coal power be considered:
:)
fossil fuel?
solar power?
...or nuclear power?
then that song started playing, and the caveman threw the bone up into the air, next thing, we're in space.
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