The theme for this week is … DNA.

As a retired medical research scientist I was excited when DNA arrived on the genealogical scene. But I soon realised that my early knowledge was seriously outdated – here was a whole new world.

DNA analysis has certainly helped settle a few genealogical questions. So far there have been no surprises, welcome or not, in my own family; just confirmations and a few distant cousins to discover.

The most useful was in my paternal Great Great Great Great Grandfather’s family. Thomas Cochrane 1733-1804 and his wife Ann Kerr 1733-1789 had ten children, according to a huge old family bible – an absolute treasure trove. In addition, Thomas Cochrane left a will. So I know for certain who his children were and who most of them married.

But the bible records, which I have put up on various genealogical sites, has not deterred a number of people from claiming that Thomas and Ann were their ancestors, that they had children with other names (some at improbable dates), and that various of their children married other persons not mentioned in the bible. The main problems are that Thomas, Ann, Margaret, Jean, James, John, etc. were very common names in those times, it was not compulsory to register baptisms and also the surname Cochran(e) was very common in Renfrewshire. So it is very easy to claim ancestors who are not (!).

DNA helped me unravel such a line. Thomas and Ann’s daughter Margaret Cochrane, born 19 August 1760, married a weaver named Peter Stewart Donald according to her father’s will. But several people claim she was the wife of a completely different man and had several children with him.

Records show that Margaret Cochrane and Peter Stewart Donald (1757-) married and lived in Dunbartonshire where they had at least two children, Jane (or Jean) Donald 1780-1864 who married Robert Hillhouse, and Janet. This has been confirmed via a DNA match with a Hillhouse descendant.

A fuller story of the Margaret Cochrane above and several other Margarets, all related, is at http://www.nancyvada.me/the-five-margarets.