Do DNA tests measure ethnic purity?

[Vixen]

I noticed that a poster claimed ethnic purity as a 23+me DNA test showed he was 100% 'northwest European'. Others claimed he photoshopped the results and in any case the commercial DNA tests were not reliable as to ethnicity.

I did notice that a UK Forensic centre was requesting DNA samples from three main ethnic groups: European, Asian and African, so it would appear that ethnicity is a self-description, as the forensic police needed a database of those ethnicities before they can say they are looking for suspects of any particular group, with confidence.

Also, it seems to me that the more 'alpha' successful homo sapiens are more likely to travel or migrate and thus the idea that having 'just one ethnicity' in a DNA profile is not necessarily 'superior'.

What do people think?

 

[marplots]

DNA doesn't even measure gender "purity."

 

[ctamblyn]

My dictionary says ethnicity is "the fact or state of belonging to a social group that has a common national or cultural tradition". That doesn't​ sound like the sort of thing that a DNA test can resolve.

 

[abaddon]

I noticed that a poster claimed ethnic purity as a 23+me DNA test showed he was 100% 'northwest European'. Others claimed he photoshopped the results and in any case the commercial DNA tests were not reliable as to ethnicity.

I did notice that a UK Forensic centre was requesting DNA samples from three main ethnic groups: European, Asian and African, so it would appear that ethnicity is a self-description, as the forensic police needed a database of those ethnicities before they can say they are looking for suspects of any particular group, with confidence.

Also, it seems to me that the more 'alpha' successful homo sapiens are more likely to travel or migrate and thus the idea that having 'just one ethnicity' in a DNA profile is not necessarily 'superior'.

What do people think?

It was quite clearly photoshopped as the image in question contained a jumble of partial results from two different DNA companies and bore no remote resemblance to the way either of those companies present their results.

 

[Vixen]

It was quite clearly photoshopped as the image in question contained a jumble of partial results from two different DNA companies and bore no remote resemblance to the way either of those companies present their results.

Agreed. There is usually 0.03% (or similar) that is 'unassigned'.

In addition, someone who shows as 98% 'British' is almost certainly Irish or Scottish as the English are a mix in common with the French and the Germans, so paradoxically, the ethnic groups not considered 'English' are purer British than the English Brits.

 

[arthwollipot]

"Ethnic Purity" is a meaningless term.

Sorry - it's a meaningless biological term. It has plenty of meaning as a political term.

 

[abaddon]

Agreed. There is usually 0.03% (or similar) that is 'unassigned'.

In addition, someone who shows as 98% 'British' is almost certainly Irish or Scottish as the English are a mix in common with the French and the Germans, so paradoxically, the ethnic groups not considered 'English' are purer British than the English Brits.

And why is it that out of the plethora of results pasted into the borked image that one of the most important results to paste into that patchwork quilt was "Ashkenazi 0 percent"?

Revealing, no?

 

[marplots]

And why is it that out of the plethora of results pasted into the borked image that one of the most important results to paste into that patchwork quilt was "Ashkenazi 0 percent"?

Revealing, no?

(((Ashkenazi)))

 

[Skeptic Ginger]

No such purity exists short of a few individuals in long isolated populations who haven't mixed. The entirety of the human population has been mixing since homo sapiens evolved.

Ashkenazi Jews are another exception with a lot of inbreeding.

 

[Skeptic Ginger]

"Ethnic Purity" is a meaningless term.

Sorry - it's a meaningless biological term. It has plenty of meaning as a political term.

This ^ is accurate. It is also accurate that the popular commercial genetic tests for seeing who your ancestors are, are highly imprecise.

 

[Giordano]

There are really two questions here: one the concept of race which is not a scientific one and one that DNA analysis does not reveal in the way that many people seek to interpret it (it can tell you that you have certain alleles or haplotypes that are common in certain populations and that therefore some of your ancestors were probably from that population, but it doesn't map onto ideas of "race" as most people use the term).

Second is the post by the Forum member, which was clearly bogus. This particular member has often posted self-admitted racist views, but I was still surprised that they would make up "proof" of their own "racial purity." Are their racist posts really any more accurate of their true views than their 23 and me report?

 

[Hercules56]

Sort of.

If you are 100% Irish, 23andMe will tell you so.

If your are 25% Irish, 25% German, 25% Ashkenazi Jew, 25% Arab, they will also tell you so.

 

[Hercules56]

My 23andMe result says I was 95% Ashkenazi Jew, 3% Eastern European, and a bunch of other things like East Asian. I am 0% African.

My male haplotype is R1a1a1.

 

[Skeptic Ginger]

My 23andMe result says I was 95% Ashkenazi Jew, 3% Eastern European, and a bunch of other things like East Asian. I am 0% African.

My male haplotype is R1a1a1.

But the problem with that is, all of us are out of Africa. So their report is inconsistent with what we know about the human genome.

Though you may very well have a significant proportion of genetic inheritance from your Ashkenazi Jewish ancestors.

23 and Me, like Ancestor.com are looking at a very limited number of genetic markers out of the 3 billion base pairs.

Wiki has your haplogroup covered.

 

[Hercules56]

But the problem with that is, all of us are out of Africa. So their report is inconsistent with what we know about the human genome.

Though you may very well have a significant proportion of genetic inheritance from your Ashkenazi Jewish ancestors.

23 and Me, like Ancestor.com are looking at a very limited number of genetic markers out of the 3 billion base pairs.

Wiki has your haplogroup covered.

That's wonderful, but the fact is 23andMe can identify someone's heritage with pretty good accuracy, by a DNA test.

They got me down very well.

Sure, my ancestors 40,000 years ago came from Africa.

But our genetic history doesn't end when we were in Africa.

Mutations took place after that, and continue to take place.

Sounds like some folks are offended by the idea that we can identify people's geographic lineage, using genetics.

 

[marplots]

That's wonderful, but the fact is 23andMe can identify someone's heritage with pretty good accuracy, by a DNA test.

About as useful as looking in phone directories for your last name.

They got me down very well.

How could you possibly know? Other than, "Well, that's what they said."

 

[Giordano]

That's wonderful, but the fact is 23andMe can identify someone's heritage with pretty good accuracy, by a DNA test.

They got me down very well.

Sure, my ancestors 40,000 years ago came from Africa.

But our genetic history doesn't end when we were in Africa.

Mutations took place after that, and continue to take place.

Sounds like some folks are offended by the idea that we can identify people's geographic lineage, using genetics.

No- it's just a lot more complicated than that. In fact, what exactly is Ashkenazi Jewish (which is my ancestry too) for that matter? Do you think that even in our relatively inbred population we don't share most of our alleles with other populations? That there hasn't been significant gene exchange along the way? What do you think our genetics looked like before the Diaspora and what happened since?

Yes, 23 and me can let you know some about from which populations you obtained your DNA. My point is how that really maps onto ideas of race or ethnicity. Frankly I've tried to discuss that in other threads but it really deserves a full chapter in a textbook. The bottom line is: don't take it all too seriously. Have fun with it, and the idea of relating it to geographic origin is not too bad, but race is not a scientifically meaningful term.

 

[Aepervius]

There are a few genetic marker which can somewhat accurately associate you to a certain group. Particularly population which are known to have a rare genetic defect rarely found outside their group, and/or have an homogeneity of dna among the group e.g. the population is homogeneous due to a genetic bottleneck. Ashkenazim group at least belong to one of those category and are identifiable as such, so I would not be surprised to see it listed and effectively detected.

 

[Aepervius]

No- it's just a lot more complicated than that. In fact, what exactly is Ashkenazi Jewish (which is my ancestry too) for that matter? Do you think that even in our relatively inbred population we don't share most of our alleles with other populations? That there hasn't been significant gene exchange along the way? What do you think our genetics looked like before the Diaspora and what happened since?

There are shared allele , but this is not what testing concentrate upon. That would be a waste of time. There are on the other hand some combo mtDNA, YDNA and normal DNA which is in combination is rarely found outside a certain group. There is a reason why some ethnicity are often used in genetic research, because they offer a certain uniformity which is rarely found outside.

 

[Vixen]

But the problem with that is, all of us are out of Africa. So their report is inconsistent with what we know about the human genome.

Though you may very well have a significant proportion of genetic inheritance from your Ashkenazi Jewish ancestors.

23 and Me, like Ancestor.com are looking at a very limited number of genetic markers out of the 3 billion base pairs.

Wiki has your haplogroup covered.

Not a hundred percent 'out of Africa' as Asians and Europeans usually have an element of Neanderthalsis (up to 4%), not found in Africans and a separate species of homonids.