ScienceInsider has some reactions to plans from the UK Border Agency to use DNA tests to verify claims of asylum seekers that they do in fact come from the countries they claim (e.g., Somalia), rather than other ones which do not face the same geopolitical turmoil. This is a real problem for European countries, as many illegal immigrants without documents claim to be from war-zones.
I am completely in agreement with the use of DNA tests to substantiate asylum seekers' claims, with the caveat that the followed protocols should be transparent to the scientific community, so that they can be subjected to scrutiny. Right now, many DNA testing companies make bold assertions of being able to distinguish one ethnicity from another, but given that their methods are "closed box", their results are suspect.
However, it is completely inaccurate that DNA is unrelated to ethnicity. Both simple uniparental tests (Y chromosome and mtDNA), and of course autosomal panels, are useful in updating (via Bayes' rule) one's prior belief in a particular hypothesis.
A combination of linguistic assessment (whether someone knows the language of the country he claims to be form), tests of common knowledge (whether someone knows some simple facts about that country), and a DNA test (whether someone has DNA that is common in this country) is enough to determine whether someone is from some claimed origin.
Such determinations are never foolproof, but there really is no foolproof method of determining that a person with no papers is in fact what he says he is. However, they can, in fact, both statistically confirm or reject a great number of cases with very high probability of being right. This, in itself, is a great improvement.