DNA testing is becoming more and more integrated into our traditional genealogical research. Over 1.5 million people have completed some form of autosomal DNA test, testifying that the idea has finally taken root and now is almost a commonplace notion.
However, with widespread success of autosomal DNA testing at companies like Ancestry DNA (click and use code for free shipping through March 31, 2016: FREESHIPDNA) and 23andMe, the two other kinds of DNA tests are often overlooked. The Y chromosome DNA test, or yDNA, traces a direct paternal line. The mitochondrial DNA test, or mtDNA, traces a direct maternal line. Both are offered by Family Tree DNA. Is there a place for these tests among your genealogical research?
I say yes! One of the biggest limitations of autosomal DNA testing is that it cannot reliably reach back past the fourth or fifth generation in your pedigree. But both yDNA and mtDNA can.
Let’s focus on mtDNA. Remember, mtDNA is directly maternally inherited, meaning that you have the same mtDNA as your mother and all of your siblings. It is the same mtDNA as your maternal grandmother, and her mother, and so on, for ten generations or more.
When and how would you use mtDNA testing?
1. You need to grab your mtDNA before it’s gone
You have an ailing great aunt, or you yourself are one of the last remaining carriers of your mother’s mtDNA.
Having your mtDNA tested first and foremost creates a record of your direct maternal line. Just as you would obtain a birth certificate or marriage license for your ancestor to see what other important genealogical information it might contain, having a record of your mtDNA is an important part of documenting your maternal line.
2. Unknown ethnicity
You have a female ancestor whose ethnicity is unknown. Perhaps you think she is Native American or African American.
Along with your mtDNA profile, which helps you make connections with others, taking an mtDNA test gives you a haplogroup, or a deep ancestral group. There are different haplogroups for different world regions and populations. Sometimes knowing your haplogroup can help either confirm or dispel a family rumor about the heritage of a particular ancestor. Though for most it will just verify what you already know, like confirming that your maternal line is from western Europe.
3. Unknown origins
In 1873, aliens must have deposited your female ancestor in Virginia.
If you have tried every other avenue to discover your ancestor’s origins, and currently your best theory of her origins revolves around extraterrestrial beings, you can try mtDNA testing.
The results of the testing will provide you with a list of individuals who may share direct maternal line ancestry with you, and therefore might be related to this mystery ancestor. However, that shared ancestor could be as recent as 1873, or as distant as dates that require the post nominal “BC.” So, it is more or less a shot in the dark. But hey, if you don’t shoot, you will definitely miss!
In general, mtDNA testing should not be the first test you turn to when seeking out your ancestors. But it does have its place in your genealogical toolbox, so don’t be afraid to pull it out once in a while.
To get started, I recommend my Mitochondrial (mtDNA) DNA for Genealogists quick guide. It covers the basics of mtDNA testing and more on how to use it in your family history research. If you’re looking for more help with using DNA in genealogy, consider my entire series of DNA quick reference guides or come find me at YourDNAGuide.com.