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Humanity's Genetic Diversity on the Decline
jd writes "In a study covering five different periods of history, from 300 AD to the present day, and geographically spread across much of Europe, scientists have extracted the mitochondrial DNA from a sizable number of individuals in an effort to examine changes in diversity. The results, published in the Royal Society journal is intriguing to say the least. 1700 years ago, three out of every four individuals belonged to a different haplotype. In modern Europe, the number is only one in three. The researchers blame a combination of plague, selection of dominant lineages and culturally-inflicted distortions. The researchers say more work needs to be done, but are unclear if this involves archaeology or experiments involving skewing the data in the local female population."
Come on down to Southern Ohio and you'll see just what I mean. The Shadow Over Portsmouth!
"He who can destroy a thing, controls a thing." --Paul Atreides, Dune
In the name of science, I volunteer for any experiments involving "skewing" "data" into the local female population.
Firstly, the article has nothing about "human genetic diversity". It's about ancient UK population having larger haplotype diversity than the many modern European populations.
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There could be a few reasons to this. Anglo-Saxons came to England around 550AD. Also Romans had settled the island. Later also Vikings came. These plus the local population already implies quite a lot of diversity.
Since then some lineages have been more successful, that's it. Actually, this could be considered supporting evidence for D. Gregory Clark's hypothesis that upper classes have been replacing the lower ones during middle ages in England, as reported by Slashdot yesterday, see http://science.slashdot.org/article.pl?sid=07/08/
They used a historic sample of only 48 ancient Britons and those were even spread out to a timeframe from about 700 years (contrary to the summary, the ancient samples lived between AD 300 and 1000 which is a relatively big timeframe).
I would think that their analysis could still be statistically relevant, but still they say themselves that more work is needed, so I think more historic sample data would be quite useful.
Their conclusions are not valid for all of humanity anyway. How does Western Europe equal humanity? It is already known that there is less genetic diversity in two Europeans from different countries than there is in two Africans from the same village. What a Eurocentric point of view.
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If they eliminated the outliers, such as West Virginia, the average human diversity would go back to what it was in 300AD.
So, as I understand it, this was written by an unattractive British science geek as a pickup line to use in bars full of attractive women.
"Hi. We analysed the historical genetic diversity of human populations in Europe at the mtDNA control region for 48 ancient Britons who lived between ca AD 300 and 1000, and compared these with 6320 modern mtDNA genotypes from England and across Europe and the Middle East. We found that the historical sample shows greater genetic diversity than for modern England and other modern populations, indicating the loss of diversity over the last millennium. The pattern of haplotypic diversity was clearly European in the ancient sample, representing each of the modern haplogroups. There was also increased representation of one of the ancient haplotypes in modern populations. We consider these results in the context of possible selection or stochastic processes. So, you understand... you... must have... sex.... with me."
"Are you trying to tell me that the genetic diversity of Britain is at stake if I don't hop into the sack with you?"
"Umm... yes."
"Yes, then. For Britannia and the queen!"
No, it isn't. For one thing, diversity is itself a survival trait in a population -- a population that had actually all zeroed in on the one single 'most fit' genotype would be terribly vulnerable.
It's misconceptions like these that make it easier for cranky American Protestants to think of 'Evolutionism' as just another faith.
Whence? Hence. Whither? Thither.
I know! What a bunch of malarky. Everyone knows that North America equals humanity, not Western Europe. Duh!
Nobody said "fittest" is an absolute, nor even measurable. It just means "whatever has the best chance of survival in this environment". If any variable changes (such as the environment), it's likely some other trait becomes more "fit". As such; in an environment that changes rapidly, a more diverse genetic will have bigger chances, in a more stable environment, genetic markup would have the time to zero in on a particular direction. This vulnerability you describe only exists when one of the variables changes. Diversity may be (and probably is) a better trait in the long term, but in the short term it serves little purpose. There's probably millions of times in the past where diversity in human genes has grown, we happen to live in a time and environment that is stable enough for other traits to become more important than diversity and so these other traits tend to be the ones with the biggest chance of survival.
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While you are indeed a prime example of what you describe, I don't think the issue is as widespread as you suggest.
I like basketball!!1!
Most importantly, it is the correct combination of genes that makes a successful organism as well as individual genes. 'Mixing' of groups of people is hugely advantageous for this reason.
Secondly, genes do not become lost when they combine with genes from another person to make a child. There is just a new combination of genes which can contribute to the whole genetic diversity of mankind. For example, we could take the idea that races should not interbreed a little further and say that people should not breed outside of their immediate family. The problem with this would be that genetic diversity could hardly ever increase, and by attrition mankind would be doomed. By separating races one creates several smaller separate gene-pools each of which is smaller than the original whole and hence more vulnerable.
Thirdly, by separating the societies it would become genetically/evolutionarily advantageous for one race to think of or treat the others as subhumans. By this argument I claim that you have implicitly invoked Godwin's law.
Also, I wish you luck procreating with your sister...
There have been many catastrophic losses of biodiversity on the planet and there will certainly be more before the Earth becomes barren.
I don't agree that the loss of societal habits, misconceptions and bugbears ("human culture") can be equated. These things may be dear to people but they are mostly rubbish.
Rich And Stupid is not so bad as Working For Rich And Stupid.
That's hard to say. The ease of travel has been leading to a decrease in diversity within a species which is significantly less diverse than most other species already.
But as was pointed out in an article I read last year, what diversity looks like may very well be in transition. I don't personally quite buy the authors suggestion, but the trend is away from distinctive racial groups and more towards groupings based upon intellect and looks.
Which to some extent makes sense. The premium that most groups place on mating within the same group has been decreasing, at least around here, and people will always choose somebody that they find enjoyable to be around to those that are not. Frequently looks, intellect, sense of humor and health are considered selection criteria. So the idea that the groupings would be based upon that wouldn't be too outlandish.
Not at all. Me thinks you do not understand the concept of scientific reasoning as well as one might hope. It is a theory 'not based on the existence of a creator', which is a far cry from 'a theory based on the NON-existence of a creator'. Not assuming the existence of a 'creator' (whatever one may choose to mean with that) one does ones best to understand and explain observed phenomenon in a rational manner. While one cannot yet prove that the flying spaghetti monster does or does not exist through repeatable experimentation (and people should feel free to contribute their research in this area to the scientific community as a whole), one can make a very good description of the functioning of the world around us without having to tackle the issue of the influence of his omnipotent noodly appendages.
I went to a US public school where our principal told the senior class that we were damn well going to go to a prayer session before graduation or we wouldn't get our diplomas, despite a Supreme Court ruling the same year that held that even holding such a ceremony was definitely illegal. Yeah, our entire school system is run by a bunch of atheist communists who hate religion. Right.
This oppression is also why it's absolutely impossible to get elected President unless you're an avowed Atheist.
Don't blame me; I'm never given mod points.
IN A.D. 2101, WAR WAS BEGINNING
(lameness filter encountered. I suppose the mods will decide if it's accurate or not. Personally, I think this parenthetical bit ruins the joke. Lame.)
Your brain is not a computer.
When you have a theory that explains the natural world as perfectly as evolution does, invoking a creator just because not having one makes you uncomfortable is a terrible unparsimonious thing to do. If there's a bias here, it's that science tends to favor the simplest explanation that can explain the observed facts.
(And that's without even going into the massive amount of questions invoking a creator invokes in the first place.)
Keep in mind, though, that evolution is not a theory about the origin of the universe, just about life. If you really want a gap for your god to hide in, have him hide "before the Big Bang".
When you send huge portions of your peak reproductive populaiton through the meat grinder in the span of about two generations, you can probably expect a decrease in genetic diversity. The good news about the next World War is that it will be nuclear and with all the radiation will come mutations which should help out with the genetic diversity issue.
Sheesh, evil *and* a jerk. -- Jade
How is it any less complex than a "part" of the universe suddenly appearing and spontaneously creating the rest? Neither has a cause. Linguistic complexity doesn't really determine causal complexity. Case in point: note that the "God theory" can be summarized as "a part of the universe, called God, appeared and spontaneously created the rest." The Big Bang can be summarized as "a part of the universe, called a singularity, appeared and spontaneously created the rest."
After all, I am strangely colored.