Can DNA be used to indicate specific ancestry?

[syncrolecyne]

For instance, lets say someone is adopted and has no idea who there parents were, other than they were “white” people. Could a DNA test prove that the person had in all likelyhood a Irish father and a Polish mother?

Perhaps that is too specific, but could DNA establish things such as whether a person really did have a Native American great great grandmother, or is entirely European, or whether someone is part subSaharan African or not? In all the debates over race and genes, I have seen things that either suggest these things can be done.

Also lets say two people’s DNA data are compared. Can a degree of relationship beyond immediate family be established. I know DNA can prove paternity or maternity to a great degree, but could DNA prove that two people are most likey distant cousins with a fairly recent ancestor?

I know these are a lot of questions, and involve debatable issues, but I think there are factual yes or no answers involve.

[Davebear]

*Originally posted by cuate *
Could a DNA test prove that the person had in all likelyhood a Irish father and a Polish mother?.. could DNA establish things such as whether a person really did have a Native American great great grandmother, or is entirely European, or whether someone is part subSaharan African or not…

In theory, absolutely. Whether our knowledge and ability has reached that point, yet, I’m not sure. We would need to have a ‘dictionary’ of baseline markers that identify a subject as having a particular heritage. I don’t know if that’s been created, yet, or even if we’ve determined what the markers are.

**
Also lets say two people’s DNA data are compared. Can a degree of relationship beyond immediate family be established. I know DNA can prove paternity or maternity to a great degree, but could DNA prove that two people are most likey distant cousins with a fairly recent ancestor?**

Yes. This is currently being done.

[Ringo]

Interesting article here, from early 2001. Some snippets (most of which are the author quoting other people):

The (DNA Diagnostic) Center, in response to my question about establishing one’s Native heritage said:
“To date there is no test which can determine a person’s race or heritage. We can perform DNA testing to determine parentage, but not whether someone is of a particular racial or ethnic origin. If there is a match or biological relationship within the Native American population between two or more persons, to my knowledge there must also be supporting documents to provide the proof of all facts and then must to be considered by the Native American counsel. DNA testing is the most conclusive and widely accepted method to test for paternity to date (over the use/method of HLA testing.)”

Cellmark Diagnostics indicated that racial typing is not done nor were they aware of a test that would provide that information.
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Dr. Patrick Beatty, Division of Hemotology at the University of Utah Health Sciences Center and a member of the team studying HLA gene and haplotype frequencies in the North American Population for the National Marrow Donor Program, notes, “All I can speak to is HLA, not other genetic tests: I know of no HLA markers which are unique to Native Americans, or for that matter, any other major racial/ethnic category.”

In addition, the American Anthropological Association has gone on record as saying:

“…it has become clear that human populations are not unambiguous, clearly demarcated, biologically distinct groups. Evidence from the analysis of genetics (e.g., DNA) indicates that most physical variation, about 94%, lies within so-called racial groups. Conventional geographic “racial” groupings differ from one another only in about 6% of their genes. This means that there is greater variation within ‘racial’ groups than between them.”
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Highlights and observations from the President’s Cancer Panel Meeting, Concerns of Special Populations in April 9,1997 indicate:
“all disciplines present, it was agreed that the biological concept of race is no longer tenable; rather, race is a social construct-a product of the Nation’s social and political history.”
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The panel goes on to say, “While the frequency in genetic variation may differ across classically defined racial groupings, race is neither defined by any collection of genetic variations nor does an individual’s self identification according to race, predict genetic characteristics of that individual.”

There’s lots more in the article, where the author does mention:

One of the more noted migrationists indicated that there may be as many as 6-10 unique mitochondrial indicators unique and present for up to 99% of the Native populace. The caveat to such a percentage though is the limitation of mitochondrial heritage. If one’s female relations (mother, grandmother, etc.) are not of native ancestry the supporting DNA would not be present as these genetic factors are only passed on through the mother. Unique Y chromosome polymorphisms may be found and identified that would also indicate heritage as the science of genetics evolves.

For now, while there are indeed some unique qualities in and among the Native populations, there is no one rule or one unique test to provide uncontestable measure of Indian that would apply to ALL those of Native descent.

Another site, for The GeneTree DNA Testing Center includes this:

mtDNA Analysis and Y chromosome Testing
GeneTree’s Ancestry Testing Services provide the opportunity to explore biological relationship questions regarding ancient migration patterns, population studies, and genealogy. These applications are currently used to reconstruct maternal lines (mtDNA), paternal lines (Y chromosome), or determine Native American Indian Ancestry.

[tomndebb]

There is a recently published report that sparked this dicsussion in GD that attempted to do something along these lines.

So far, they have not gotten anywhere near linking something as narrow as Irish and Polish ancestry. There best effort, so far, seems to indicate that various constellations of markers indicate an origin on a particular continent with only a very few ethnic subdivisions below that level manifesting themselves in the data. (And those tend to be quite isolated ethnic groups.)

The underfunded and politically turbulent Human Genome Diversity Project may someday establish something closer. I suspect that, at this time, either the HGDP or any special effort would need to rely on the Y chromosome and mtDNA observations noted in Ringo’s post. About two years ago, a report on the Jewish Diaspora used Y-Chromosome and mtDNA analysis to demonstrate the migrations and intermarriage patterns of Jews in the last 1,000 years, or so. However, I am not certain that the ebb and flow of conquest across Europe in the last 2,000 years would permit similar findings regardng today’s national or ethnic groups.

If the methodology used in the study that prompted the GD thread is seriously improved (and if humans are not simply too intermixed to make it useful), it may be possible to identify the origins of some number of people, but when we consider the “Wild Geese” of Ireland, the German farmers of Ukraine, the Teutonic Knights, the Roman legions*, to say nothing of the Huns, Vandals, Visigoths, Ostrogoths, and Vikings, I suspect that any test will have a certain probability of error.

*(In a study by the leading proponent of Y-Chromosome and mtDNA analysis in Great Britain, a few years ago, he discovered a family in Brighton who had a documented genealogy going back to near the Norman invasion who had a clear mtDNA marker indicating a many-times-great-grandmother who came from Africa.)

[Ringo]

I’d run that ebb and flow out about another 1,000 to 3,000 years, tom.

[Triskadecamus]

Good news, and bad news, on that hope is reported just this last week, at Stanford University.

Tris

“You can’t always get what you want.” ~ M. Jagger/K. Richards ~

[tomndebb]

The link that Tris supplied provides a synopsis of the report being discussed in the GD thread. (Part of the debate revolves around just what the study actually tells us.)

(Interestingly, the Stanford synopsis specifically notes the difficulty of narrowing down groups in Europe because of the migrations that have occurred.)