What I Learned From My DNA

When I started researching my family mysteries, DNA was just for Little Mix and Jeremy Kyle.  The first time I really encountered DNA testing for genealogy was when I contacted my believed 3rd cousin twice removed, David Allen, for his thoughts on my great grandfather's paternity.  David Allen had done a test which showed that he had a rare paternal haplogroup (the Y chromosome, which is passed intact from father to son) and as he was (hypothetically) related to my uncle, David Downing, via an all male line, if my uncle shared the same haplogroup, then it was almost certain that my hypothesis was correct.  I got lucky here - if there had a female in the line, if I hadn't had a willing male relative, or if David Allen had belonged to a common haplogroup, we wouldn't have been able to do this.  I could have done a standard DNA test and compared it with David Allen but as our relationship is quite distant, the chances of our relationship being detectable were about 50/50.  The tests did match, and the Allens now have pride of place in my tree. Read more...