Coronation Street stars get in on the act with DNA testing
If you are a Corrie fan you may already have watched several of the stars use genetic testing to learn about their ancestry. The results were broadcast yesterday and the programme is available on the ITV Hub for a few weeks.
The show does a great job of highlighting the importance of documentary genealogical evidence alongside DNA testing tools. Each individual starts off with Ancestry’s ethnicity estimates, but researches their relative matches using records of their ancestors' lives.
This illustrates a couple of points. Firstly, a DNA test cannot in itself tell us where we come from - it is a useful tool, in combination with genealogical records, for our ancestry research. Secondly DNA testing is extremely useful for verifying your family history. When you've drawn conclusions that link you to particular family lines, DNA can help prove or disprove these links. So while Coronation Street started with ethnicity estimates, for family history research the key part of your DNA results will be the relative matches – ie who else in the database do you share significant amounts of DNA with?
We can look at the amount of DNA we share with other people, and also how large the chunks are, to estimate our likely relationships. The more DNA you share with someone, the easier it is to answer the question of how closely related you are, eg identical twins share 100% of their DNA, and full-siblings around 50%. But when you share a relatively small amount of DNA with a match then determining your relationship can be more challenging.
To understand where a relative match fits in your family history you will want to compare your family tree with theirs. Not all of your matches will have researched their family tree, or they may not have shared this on the web, but this need not be a dead end for your research – there are some great resources to help you move forward, and some are mentioned in this earlier blog.
Which test should I take?
As you'd expect this depends on what you want to learn. A great talk from Debbie Kennett (given at Who Do You Think You Are? Live in 2015) describes the basic options available to you.
Y-DNA test: Only for men, this can be used to trace the male direct line, for both recent and more distant ancestry.
mtDNA test: For all, this can be used to trace the direct female line, for both recent and more distant ancestry.
Autosomal DNA: For all, this captures information from across our family lines. For genealogy purposes this test has a limited reach to about the last 5 or 6 generations (around 200 years). Not only does the amount of DNA we share with distant ancestors decrease the more generations we go back, but the complexity and potential overlaps of family trees mean it is quite possible to draw incorrect conclusions about the nature of relationships between DNA matches.
If you are considering a DNA test, or would like some help interpreting your results, get in touch for a free-of-charge consultation.