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."

Some points

[wandm]

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.

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=07/08/0 7/2221256 [slashdot.org]

The historic sample is kinda small

[bomanbot]

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.

It's already been explained.

[Reeses]

It's sad that scientists don't read each other's stuff. Then again, both of these articles came out at the same time, so it would have been virtually impossible.

But the parent article refers to a phenomenon mentioned in a slashdot article about the Industrial Revolution less than a day ago. http://science.slashdot.org/article.pl?sid=07/08/0 7/2221256 [slashdot.org]

Now the key is to see if the two groups catch on.

Re:Is this news?

[kahei]

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.

Anno Domini

[TheNicestGuy]

All right, if Slashdotters are going to continually jump all over misuse of "begs the question", then there's a pet peeve I'd like to add to that fervor. "300 AD", as it appears in the summary, is also incorrect usage. "AD" stands for anno domini, which is Latin for "in the year of the Lord". The phrase in Latin usage and traditional English usage comes properly before the number, not after. (Say it in full: "300 in the year of the Lord" sounds like an explanation of when something's tricentennial occurred. "In the year of the Lord 300" makes more sense as an absolute time reference.)

The convention of putting "AD" after the number is nothing but sloppy analogizing to "BC", which (being the English phrase "before Christ") does make more sense that way.

Note that the Royal Society writers did get it right. It's the Slashdot summary that's wrong.

Re:British science geeks have it all figured out

[Xtravar]

Just lie back and think of England...
http://en.wikipedia.org/wiki/Lie_back_and_think_of _England [wikipedia.org]