From Stanford University at Eurekalert:
Starting about 7,000 years ago, something weird seems to have happened to men: Over the next two millennia, recent studies suggest, their genetic diversity -specifically, the diversity of their Y chromosomes – collapsed. So extreme was that collapse that it was as if there was only one man left to mate for every 17 women.
Anthropologists and biologists were perplexed, but Stanford researchers now believe they’ve found a simple – if revealing – explanation. The collapse, they argue, was the result of generations of war between patrilineal clans, whose membership is determined by male ancestors.
…
It’s not unprecedented for human genetic diversity to take a nosedive once in a while, but the Y-chromosome bottleneck, which was inferred from genetic patterns in modern humans, was an odd one. First, it was observed only in men – more precisely, it was detected only through genes on the Y chromosome, which fathers pass to their sons. Second, the bottleneck is much more recent than other biologically similar events, hinting that its origins might have something to do with changing social structures.
Certainly, the researchers point out, social structures were changing. After the onset of farming and herding around 12,000 years ago, societies grew increasingly organized around extended kinship groups, many of them patrilineal clans – a cultural fact with potentially significant biological consequences. The key is how clan members are related to each other. While women may have married into a clan, men in such clans are all related through male ancestors and therefore tend to have the same Y chromosomes. From the point of view of those chromosomes at least, it’s almost as if everyone in a clan has the same father.
That only applies within one clan, however, and there could still be considerable variation between clans. To explain why even between-clan variation might have declined during the bottleneck, the researchers hypothesized that wars, if they repeatedly wiped out entire clans over time, would also wipe out a good many male lineages and their unique Y chromosomes in the process. More.
Well, unlike many theses in human evolution, it’s plausible (unfortunately in this case). Early societies lived all too close to nature and the resulting desperation could certainly lead to wars of annihilation. Later in history, it usually made more sense to subjugate conquered peoples and make them pay tribute. But tribute only works if the average human can produce more than he himself needs to survive.
Some questions: Why 7000 years ago in particular? What was happening just then? Human beings cannot have just suddenly discovered violence. New weapons perhaps?
This thesis would be greatly strengthened if we found considerable evidence of violent deaths in male remains from that period.
See also: Researcher asks, if ecology caused the human brain to grow so large, what about the role of language?
Human evolution researchers: Social challenges decreased brain size
Early human religion: A 747 built in the basement with an X-Acto knife
and
Human origins: The war of trivial explanations
And why just humans?
Dean_from_Ohio – actually, no. The “one male progenitor” would have lived about 200k years ago (that’s the estimate of the time when the most recent common ancestor of all y-chromosomes lived). Also, the effect is only seen in the y chromosome, so it’s a man only phenomenon.
The progenitor of the gene and the event are two different things, I’m assuming Dean is speaking of Noah’s ark, in which case one man and his 3 son’s survived, while 4 women (their wives) survived increasing the genetic diversity within women, while creating a narrow bottle neck for the Y chromosome, as it would have come exclusively from Noah. The pro generator of that Y chromosome likely lived long before the bottle neck, likely form an ancestor of Noah.
Dean – but it’s not a bottleneck down to 1 or 2 individuals, and it’s also only in men. So you would need a lot of Noahs, each with (on average) 17 wives.
jcfrk101 – the methods that are used trace the evolution of the Y chromosome back to the most recent common ancestor. If the Bible is to be believed, that would be Noah.
Dean_from_Ohio
But as Bob pointed out, this is a Y chromosome only bottleneck. There wasn’t a bottleneck in general at this time, as we’d see that in our DNA. That’s why they aren’t proposing some kind of natural disaster, like a meteor strike or volcanoes wiping out much of humanity.
Something similar may have happened in just the last few centuries. About 1 in 200 men in the world has Genghis Khan as an ancestor:
http://blogs.discovermagazine......xbB_VMvzWY
It wasn’t Genghis alone impregnating all these women (although it wasn’t for lack of effort) but his many powerful sons, and their sons, etc, many of whom were powerful leaders that traveled throughout the Mongol empire.
In future centuries as the descendants of Khan continue breeding, it will likely go from 1 in 200 to 1 in 20 and so on. As this occurs, there will be less Y diversity as other types of Y disappear – future geneticists may see a kind of bottleneck.
If something similar happened at a time when the world’s population was much smaller, the effect would be even more pronounced. According to the paper the bottleneck they see occurred over a period of 2000 years.
So Population Genetics has revealed a bottleneck for humans roughly around the time of Noah?
This ‘bottleneck finding’ matches up with the bottleneck that Robert Carter had predicted for the male lineage in this article from 2011:
Of related interest: This following study found that nearly three-quarters of mutations in genes that code for proteins occurred within the past 5,000 to 10,000 years,,,
Also of related interest, after a long drawn out debate, Dennis Venema finally reluctantly conceded that he could not rule out a ‘first pair’, i.e. an Adam and Eve.
All in all, the mathematics of population genetics has not been kind to Darwinian claims in the least. There are (at least) three devastating problems revealed by population genetics. The Waiting Time problem, Natural selection is grossly inadequate as the supposed “Designer substitute”,, and perception of reality itself become illusory.
Moreover, population genetics, besides falsifying Darwinian evolution because of the waiting time problem, also casts Charles Darwin’s main claim to scientific fame, i.e. Natural Selection itself, under the bus:
In other words, Neutral theory, and the now falsified concept of junk DNA itself, was not developed because of any empirical observation, but was actually developed because it was forced upon Darwinists by the mathematics of population genetics. In plain English, neutral theory, and the concept of junk DNA, is actually the result of a theoretical failure of Darwinism within the mathematics of population genetics!
Here are a few humorous quotes on the implications of neutral theory:
And, as if the waiting time problem and the casting of Natural Selection under the bus were not bad enough, Donald Hoffman has, through numerous computer simulations of population genetics, proved that if Darwinian evolution were actually true then all of our perceptions of reality would be illusory.
Thus, in what should be needless to say, a worldview that undermines the scientific method itself by holding all our observations of reality are illusory is NOT a worldview that can be firmly grounded within the scientific method!
Moreover, completely contrary to materialistic premises, conscious observation, far from being unreliable and illusory, is experimentally found to be far more integral to reality, i.e. far more reliable of reality, than the math of population genetics predicts. In fact, in the following experiment it was found that reality doesn’t exist without an observer.
Apparently science itself could care less if atheists are forced to believe, because of the math of population genetics, that their observations of reality are illusory!
BA77,
No. A bottleneck for the Y chromosome. But I can see why a bible literalist would jump at anything that supports his myth, yet ignore the millions that are incompatible.
Allan Keith, it is the height of hypocrisy for a Darwinian Materialist to say a “bible literalist would jump at anything that supports his myth”.
The entire Darwinian worldview is built on nothing but myths and imagination. Any time reality encroaches upon the house of imaginary cards that Darwinists have built to support their mythical worldview it all comes crashing down. But Darwinists never, ever, accept what the real world is telling then about their theory.
For instance, when John Sanford included realistic rates for detrimental mutations, it falsified “Fisher’s Corollary”, but Darwinists refused to accept the results.
Specifically, “Because Fisher did not understand the actual fitness distribution of new mutations, his belief in the application of his “fundamental theorem of natural selection” was fundamentally and profoundly wrong – having little correspondence to biological reality.”
Likewise, there are many false assumptions built into the mathematics of population genetics.
And yet, despite these many false assumptions, and as pointed out in post 8, the mathematics of population genetics STILL managed to falsify core Darwinian presuppositions.
Moreover, to add insult to injury, although every rigorous theory of science requires verification from mathematics, and experimentation, in order to be considered scientific in the first place, the reductive materialism that Darwinian evolution is based upon denies the reality of ‘immaterial’ mathematics:
Thus, in a twist of extreme irony, for Darwinian Materialists to, however haphazardly, try to use mathematics to verify their theory is for them, in reality, to tactically appeal to God to support their theory.
As David Berlinski states, “There is no argument against religion that is not also an argument against mathematics. Mathematicians are capable of grasping a world of objects that lies beyond space and time….”
As Van Til humorously stated, the Atheist is like a child who “needs to sit on the lap of its father in order to slap the father’s face”
Of supplemental note. The geological evidence for fairly recent, cataclysmic, worldwide flooding is fairly compelling:
goodusername @ 7,
Just think of the situation in reverse — if Genghis Khan is the x-great-grandfather in 1 of 200, then how many people alive in the Mongol Empire (or world) in 1200 AD have zero live descendants today? Is there a way to work out that answer? I would bet that it is a surprisingly large percentage.
Well, this makes PERFECT sense to me. But then the Celts have been clannish for as far back as anyone wants to go. You think Highland Scots left a lot of survivors after they defeated the boyos from the next glen? And in cashless societies, what are the PROFITS from a successful war? Wimmen.
Only when multi-village clans gelled into Kingdoms (first you get professional priests, THEN you get kings) was the Chief Honcho in Charge interested in PRESERVING any of the defeated males as potential laborers instead of just passing out widows as war booty. (Um, the original meaning of “shake your booty”?) So OF COURSE there was more diversity in the ancestry of the mothers than the fathers.
But there should have still been THOUSANDS of clans spread across Europe and western Asia when Civilization (people dwelling in permanent cities) showed up. How tight is the Y Chromosome bottleneck supposed to be?
cmow,
Yep, the further you go back the fewer the number of people who will have surviving descendants – but those that do have surviving descendants will have a lot.
https://www.theguardian.com/science/commentisfree/2015/may/24/business-genetic-ancestry-charlemagne-adam-rutherford
BA77 @ 10: “The entire Darwinian worldview is built on nothing but myths and imagination.”
True indeed. The a/mat delusion is very strong.
In this case the “bottleneck” occurred independently (and only approximately at the same time) in multiple populations. Not very Noah-ish.
Frankly, it’s much more likely to be about selection on the Y or a switch to agricultural lifestyles than this warfare idea.
^^^^^^^^^^^^^^^^^^^^^^^^^
previous comment on this thread subject to any further unsubstantiated speculations that might come up of course.
Mean while back in the real world, billions upon trillions of protein molecules are at work in each of our human bodies, and yet Darwinian mechanisms cannot account for a single protein molecule out of those untold trillions of molecules.
Dean_from_Ohio @ 4
” Maybe I’m missing something, but the article portions above say the bottleneck effect happened between 7,000 and 5,000 years ago. The midpoint of that is 4,000 B.C. ”
The midpoint of that is 6,000 years, but still in YEC territory, especially with the assumptions they would have had to make to calculates a figure.
Actually 5,000 years ago is getting close to Noah’s Flood when the male line was reduced to one for the entire world’s population.
aarceng – the mean is 6000, but that’s 6000 years ago, which is 4000BC.
As I’ve already pointed out, the data don’t support a single male 5-7 thousand years ago, so I’m afraid it doesn’t point towards Noah.
Bob states:
And is Bob as certain of his claim as Dennis Venema was of his claim that Adam and Eve could not possibly have existed?
,,, after a long drawn out debate, Dennis Venema finally VERY reluctantly conceded that he could not rule out a ‘first pair’, i.e. an Adam and Eve.
And please bear in mind, the math of population genetics is loaded with unsubstantiated assumptions:
Bottom line, take any claims from Darwinists about population genetics with a large grain of salt and keep a hand on your wallet.
Moreover, the Y Chromosome in and of itself is antagonistic to Darwinian presuppositions:
And yet, despite finding such “dramatic renovation”, they find the Y chromosome to be stable in its gene content:
ba77 @ 19 – yes. Just look at Fig. 1 of the paper & count the number of lineages in the Y chromosome tree 10kya ago. It’s absolutely clear that the data are saying that there was quite a few more than one man around 5-7 kya.
RCCF 7k YA calibrates to shortly after the 1996 anno mundi dispersion from Bavel, thus more isolated groups of the 70 families.
reference RCCF framework for understanding science.
But, rather curiously, not for the rest of the animal kingdom.
YECism works in mysterious ways.
Bob, Ignoring all evolutionary assumptions built into the estimate of course.
Moreover, if you trust this so much, why do you not trust Hoffman’s findings from population genetics that found, if Darwinian evolution were true, all your observations of reality would be illusory? (see bottom of post 8)
It is very telling of your philosophical bias against Theism that you will unquestionably accept those findings from population genetics that go against Theism (YEC in this case) and yet, on the other hand, completely ignore those findings which directly falsify Darwinian evolution as a viable scientific theory in the first place.
You can’t have it both ways Bob.
Per Mung at 22, first off, I’m not a YEC, secondly, how do you know? Genetics is still very much in its infancy, and the much more reliable geologic evidence we have supports worldwide cataclysmic flooding approx. 13,000 years ago (see bottom post 10)
ba77 – I trust what the data is saying because it’s presented (see Fig. 1 of the paper). I haven’t commented on Hoffman, so I have no idea why you would assume that I don’t trust his findings. I haven’t looked at his work, so I can’t really comment for its validity, and from the quote you give I don’t see how it’s relevant to the dating of coalescent events and their interpretations, which is what we’re discussing.
Well Bob, do let us know if their is ever any finding that will ever persuade you that Darwinism is wrong:
Myself, I can find numerous fatal flaws in Darwinian theory that prove that it is irretrievably wrong: