DNA for your ancestry - how to use DNA in family history

Discover how to use DNA to enhance your family tree research with our guide to what DNA tests are available and what they can tell you about your ancestors.

Ever since DNA tests first became part of the family tree community back in the year 2000 to help with genealogical research, they have seen big increases in popularity.

Now with several different tests offered by different DNA family tree companies, how do you know which test is the right one for you? And what might you discover from your DNA test results? Here we look at the basics to give you a better idea of how to use DNA as part of your family tree research.

Why use DNA for family tree research?

There are several reasons why you might want to do this, such as:

• To verify your paper trail research
• To help to overcome a long-standing puzzle on your family tree
• To find new relations and new branches of your family tree
• To make sure that you have used all possible tools to help you research an accurate history of your ancestors

What sort of DNA tests are there for family historians?

There are three main types of DNA tests used by family historians:

• The Y-DNA test - this is used by men to trace their direct paternal line. The Y chromosome is passed from father to son (just as surnames tend to be) and so a Y-DNA test is the tool for the job if you wish to research your paternal line.
• The mt-DNA test - this is used by both men and women to trace their direct maternal line. While the mt-DNA is passed from a mother to both her daughters and her sons, it is only her daughters who will, in turn, pass it on to their children.
• The autosomal test - this is used to test the DNA you inherit from all your lines of ancestry.

Sometimes this is called a ‘deep ancestry’ or a ‘family finder’ test. It can be taken by anyone and will show a broad picture of their genetic inheritance.

What can a DNA test tell me about my ancestry?

Your DNA results will be able to match you with relations worldwide who have taken a DNA test, both those that you know about and those you are yet to meet. Analysing your test results, the DNA databases will spot matching strands of shared DNA.

Find out more about DNA and your family tree research

• To learn more about DNA testing for family history purposes, visit the website of the International Society of Genetic Genealogy
• To track down matches with other people who have taken a DNA test, but who have used a different DNA testing company to you, go to GEDmatch 
• To see how surname researchers are using DNA to help with their studies, see Surname DNA Projects

Family tree DNA top tips

• Be prepared for surprises - for instance, if your Y-DNA doesn’t match those of other men in a DNA-Surname project, it could mean there’s been a ‘non-paternity’ event (as family historians politely call it).
• Keep an open mind - you may make discoveries about your ancestry that come as a complete surprise - lineages from other parts of the world about which you had no former clue, for example. While this can be unexpected, it’s also part of what makes DNA genealogy so interesting.
• DNA tests don’t replace traditional family history research by any means, but they are another very useful tool to help you find your deep ancestry from centuries past and to help you make connections with new-found relations from all around the world today.