“Whatever you can do to feel a connection to your [biological] ancestors is worth doing. Genetically, they are a part of you. You should know who they are.”- Diahan Southard, genetic genealogist
Using DNA testing to enhance your ancestral discovery needs both skills as a genealogist and information about genetics, according to Diahan Southard, a genetic genealogist, during a Thursday afternoon session of Rootstech 2015.
Southard outlined what you need to understand about DNA testing when seeking your family history.
Basic DNA Testing Overview
All DNA testing uses the same basic sampling method. You order the test online from one of 3 potential companies, depending on the test you desire (described below) and options available, and are sent a kit. You send back either a cheek swab or saliva sample, which the company then uses to extract your DNA. In return you’ll receive an e-mailed report identifying such things as potential relatives (those who also sent in DNA and are closely matched with your DNA) and ancestral geography (where your ancestors may have originated thousands of years prior).
There are three tests available that may help with family discovery: Y-DNA , mtDNA, and atDNA.
Y-DNA Test
Why Y-DNA is Used by Genealogists- Also known as a “Y-chromosome test,” this tests the direct male lineage. Passed nearly unchanged from father to son, the Y chromosome can then be used to trace back a direct paternal line ancestor. Any two men who have the same Y-DNA also then share a common paternal (i.e., male) line ancestor (e.g., your father’s father’s father). Women do not have a Y chromosome and so cannot take the test.
Where is the Y-DNA Test Available? As of this writing only 1 company offers Y-DNA testing: FamilyTreeDNA.
Is the Test Recommended? Southard recommends this test for everyone seeking information on the direct male line.
mtDNA Test
Why is mtDNA is Used by Genealogists- Also known as a “mitochondrial DNA test,” this tests for the female lineage. Mitochrondrial DNA is passed from a mother to all her children. While each child carries mitochondrial DNA, only females pass it on to the next generation. The test can reveal information about your mother’s mother’s family for example.
Where is the mtDNA Test Available? Currently it is offered by FamilyTreeDNA.
Is the Test Recommended? Southard indicated the number of matches can be particularly high with, making them “not your most useful test.” She stated it is “more pricey and often not genealogically valuable,” however, if you decide to pursue this test her best recommendation is to do the full, rather than partial, sequence mtDNA test.
atDNA
Why is atDNA Used by Genealogists? Also known as “autosomal DNA testing,” it is not limited to a direct male or direct female line, as it tests your entire genome, half received from your mother, and half received from your father.
Where is the atDNA Test Available? 3 companies currently offer this test; FamilyTreeDNA, AncestryDNA, and 23andMe.
Is the Test Recommended? According to Southard the test is “only helpful to about 6 generations” as there is not enough DNA passed on from ancestors further back to have valid and revealing results. In addition, work is not complete when you receive results. The test reveals *possible* cousins for example, so you’ll need to be prepared to research and contact your matches to find common ancestors. Also, “ancestral origins given are interesting, colorful, and can be useful,” stated Southard.
Final Recommendations
Southard summed her recommendations-A YDNA test is useful for researching the biological male line. A mtDNA test is more expensive and not as likely to be useful, but if you’re searching for a particular female ancestor and have few leads, it may be worth it. An atDNA test is useful for 6 generations back but takes your genealogical discovery efforts as well to take full advantage.
“Whatever you can do to feel a connection to your [biological] ancestors is worth doing. Genetically, they are a part of you. You should know who they are.”- Diahan Southard, genetic genealogist
Have you tried a DNA test to reveal your genetic heritage? Tell us about your experience in the comments section below!
