The best book that has ever been written is in us and now we have the opportunity to read it.
(V. Utt, DNA Day 2012)
Genetic genealogy uses data from DNA testing as a powerful tool to help you break through those brick walls to expand your family tree, confirm and find new relationships in your family tree, meet new cousins, join international surname projects and collaborate with a growing community of genealogists engaging in this exciting new technology that is rapidly expanding into new pioneer frontiers of science and family history. These are certainly exciting times!
Who should take the DNA test?
Because DNA testing for genealogy is most productive for looking into your family tree over a span of about five or six generations, it is very important to test family members in the oldest generation first, as that will help you move further back into family tree. Then depending on your own family tree research goals, testing other family members will be useful in refining your research and opening up new areas of exploration. It is even possible to create a complete picture of your own genetic makeup and identify which bits of your own DNA you got from any of your great-great-great-grandparents. You are literally a jigsaw puzzle made up of DNA pieces from all of your ancestors, and now we can identify those pieces with remarkable certainty.
Which test is most useful?
Each DNA test has a different goal, so it depends on your own family tree questions as to which test is most appropriate. However, the first test to do is the ‘autosomal DNA’ test, which is the standard test offered by the major testing companies AncestryDNA, Family Tree DNA (‘Family Finder’), My Heritage and 23andMe. This test reveals the unique DNA signature that makes up each person and is like a patchwork quilt of the DNA inherited from all of their ancestors.
There are also two very specialised tests that might be considered useful after this initial test, which answer specific questions about DNA inheritance. The Y-DNA test, which can only be taken by male members of the family (females do not have a Y-chromosome), relates to just the paternal line of your family, going back into deep ancestral times. The Y chromosome is passed directly from father to son, along with your family name and so connects you to others who may share your surname and history.
The mitochondrial DNA test (mtDNA) provides you with information about your matrilineal heritage; that is, it traces the direct line of your mother to her mother and back into deep ancestry. You can take the mtDNA if you are male or female. Because a woman’s surname changes with every generation it is very difficult to collaborate with other people who share the same mtDNA signature, and so it is actually the least useful of the DNA tests. Nonetheless, it may still be helpful in directing your research if your maternal lineage is unknown.
For a discussion about the differences between these tests, I recommend viewing Louise Coakley’s Genie1 page.
How much science do I need to know?
To use the test results for you family tree research, you don’t need to be a geneticist! The testing companies make it easy for you to understand your results and to connect with your genetic cousins. These companies also have wonderful resources for learning more about this fascinating field if you want to engage further. There are also many online forums, such as Facebook groups, that you can join and also professional genetic genealogists who can help you as well.
Which company should I use?
There are four major companies that offer to analyse your DNA for genealogy purposes: Ancestry DNA,Family Tree DNA, My Heritage and 23 and Me. These companies have extensive databases and are very reliable with regard to accuracy and security. You can read a comparison of what is offered by the major players in genetic genealogy on the website of ISOGG (International Society of Genetic Genealogy), a nonprofit organisation that has a wealth of valuable information on genetic genealogy. For a great overview of the pros and cons of each of the major companies from an Australian-NZ perspective, see Louise Coakley’s Genie1 page.
Where can I learn more?
If you are just starting out and want to learn more, I recommend Louise Coakley’s website as a great place to start. You will also find a tremendous amount of information and sources on Cyndi’s List’s DNA pages
I am very happy to answer your questions regarding DNA testing.