Genetic genealogy is definitely not a fad that will go away. (Remember early predictions about the World Wide Web?) To put it in non-scientific terms, DNA may be the ultimate brick-wall buster.
If you haven’t yet jumped on the train and purchased a DNA test, you should at least be reading about genetic genealogy. An excellent source is the International Society of Genetic Genealogy (ISOGG). The ISOGG wiki, a “free genetic genealogy encyclopedia with 501 articles and growing,” can be found at: www.isogg.org/wiki/Wiki_Welcome_Page
Articles about DNA studies appear in newspapers virtually every day, including the 10 Nov 2015 edition of The Telegraph. Professor Peter Donnelly writes about his research into Britain’s DNA in “The secret history of Britain is written in our genes.” He describes several distinct genetic groups, including the Dalriada in northern Ireland and western Scotland. The color graphics make the subject a little easier to comprehend. Donnelly poses both conclusions and remaining mysteries in this interesting article: www.telegraph.co.uk/news/science/11483608/The-secret-history-of-Britain-is-written-in-our-genes.html
(I believe there’s a typo in the paragraph about a single Celtic genetic group. When he referred to “Northern Island,” I think Donnelly meant “Northern Ireland.” I’m more of a proofreader than a DNA scientist.)
With thanks to FW for sending us the link to The Telegraph.