Ancestry.com's PR team sent me a few envelopes with cheek swabs in them the other day. These are part of the company's new service, DNA Ancestry, that uses genetic markers to locate you in the family tree of all humanity.
I had visions of my DNA fingerprint landing in a government vault to be used to finger me in crime I have yet to commit, so I did not rush to send off my epithelials. Instead, I got on the phone with Brett Folkman, VP of Ancestry's DNA product, to learn a bit more about the service.
Folkman assured me that the tests that Ancestry runs on its customers' samples only indicate "hereditary markers." They can't be used to identify individuals and they don't test for medical conditions. However, the lab does keep your samples in storage unless you explicitly ask them not to.
Depending on which tests you buy, you get is an indication of which paternal or maternal ancestral line you belong to, although not your exact relationship to any individual. You can find cousins you may not have known about, assuming of course that they've also taken the DNA test, or someone in their family has. If Ancestry finds a family genetic match for you and the person who's matched is open to being contacted, Ancestry proxies the e-mail, like a dating service, to allow the first communication to occur without revealing identity.
The DNA test can also be used to prove a negative: For example, it can tell if a son and father are not related.
In the future, the DNA tests will be incorporated into Ancestry.com's standard genealogical Web service. The system will "infer" genetic markers where relevant. For example, it will assume that each person in the male line of a family shares Y-DNA markers (which they will if the sons are biological children of the fathers), and will use that information to presumptively map family connections up and down a tree. If only signing up for social networks worked like this.
It's an expensive service: Individual tests cost $149 to $199, depending on the type or test ordered and gender of the test-taker. For the tests to be worthwhile, other people in your family tree also have to take them. However, since DNA Ancestry tests for heredity markers that stick with genetic lines for generations, just a few people in your tree with results could make the fee worthwhile--especially if the tests connect you with people you may not already know, or even know of.