Genetic testing - Genographic Project

Howard, some of the genetic markers are not exclusive, but linked to a population just by statistic prevalence.
Is it possible that this marker can be present with low frequency in Europe too? After all, North-Africans lived in Europe during the Roman and medieval times (Spain, Sicily etc.).

Also, is it possible that the lab just mislabeled that result?
 
littleknife said:
Howard, some of the genetic markers are not exclusive, but linked to a population just by statistic prevalence.
Is it possible that this marker can be present with low frequency in Europe too? After all, North-Africans lived in Europe during the Roman and medieval times (Spain, Sicily etc.).

Also, is it possible that the lab just mislabeled that result?
Click to expand...

This is a specific marker on the Y-chromasome, so it identifies a particular haplogroup. About 10% of the population of Northern Africa is a member of the E3a(M2) haplogroup, so there may be some mixing with European populations. National Geographic did not give me data on the abundance of E3a(M2) in European populations.

Much of their data was gathered from small isolated populations without a lot of mixing. Obviously, with modern transportation systems a member of any haplogroup might turn up just about anywhere on Earth.

Laboratory error is always a possibility. I don't have data on the error rates for this kind of typing. I suspect that error rates are fairly low, but I could be wrong. The lab may not even have a good idea as to what their error rates are. It costs $100 to get NG to run the test. If they have a systemic error in their analysis then they would just duplicate the error again. If it was a random error then a duplicate test would probably give conflicting results.

I could have another lab run a test on the Y-chromasome. However, rather than spend money reproducing the Y-chromasome test I think my next investment might be to get one of the more comprehensive tests of the whole genome, which give a stastical breakdown as to the membership in various ethnic groups, considering more equally the contributions of all ancestors. That should also help to either confirm or call into question the NG results. It may be a while before I pony up $500+ for that test though.
 
There was a recent public TV program on a project to trace some sort of genetic marker.

The scientists were trying to solve the question of why Homo sap. was so relatively late to make it into Europe, Asia being further away by far from the presumed origin of modern man.

They found this marker originated in South-Central Asia and found its way to India, Australia, the Americas and Europe. The conclusion was that the more demanding climate slowed the migrations into Europe until perhaps 1000 generations after Homo sap. had reached Asia.

Fascinating stuff.
 
Howard, thanks for the calirification. You are right, that in the case of such an expensive test and in the absence of direct medical consequence of the test result, there is no need to repeat it.
Maybe someone can provide more information about the frequency of this haplotype in "indigenous" European populations?
(By "indigenous" I mean not most recent immigrants.)
 
You must log in or register to reply here.
Back
Top