\'The myth of Celtic and Roman Britain\'

[authun]

Certainly establishing race or ethnicity of an ancient population would be that much harder.

Yes of course, and it all depends on what you are looking at.

For example, if an anglo saxon male married a british woman and had a son who then went on to marry another british woman and they too had a son, his yDNA would show him to be 100% anglo saxon. His mtDNA on the other hand would show him to be 100% british. His autosomal DNA on the other hand would probably, but not necessarily, show him to be a mixture of his parents and grand parents but also include autosomal DNA from any one of a number of their ancestors too. The genetic condition known as Factor V Leiden mutation, a blood clotting disorder, occured in one individual at some point in the past but at least one copy of it exists thoughout europe and the middle east in varying frequencies:

Lebanon 14.4
Syria 13.6
Greece-Cyprus 13.4
Jordan 12.3
Sweden 11.1
U.K. 8.9
Turkey 7.41
Germany 7.12
Spain 3.33

The above countries encompass a lot of different ethnic groups but all those people have at least one ancestor in common at some point in the past and via some ancestral route or other.

It's a popular misconception to equate ethnicity with a yDNA or mtDNA marker. Even governments are guilty and our own UK Border Agency is making this mistake with its Human Provenance Project prompting this article by leading geneticists:

"Can DNA analysis really be used to screen asylum seekers by identifying their country of origin? The immigration authority apparently believed so, and almost put such a scheme into immediate action – without, it seems, consulting academic scientists on the matter. David Balding, Michael Weale, Michael Richards and
Mark Thomas examine a worrying story."

http://www.ucl.ac.uk/mace-lab/macepdf/B ... Border.pdf

best
authun