There are times when we run into roadblocks in our quest to document our family history. That is where I am stuck, as I begin the upcoming month's research plans to explore the family of Elizabeth Howard Ijams, my mother-in-law's fourth great-grandmother. As frustrating as those roadblocks may be—and the likely reason we often refer to them as "brick walls"—in this new age of genetic genealogy, we can find a way past those research impasses. But it's not just any DNA test which provides the key to unlock the hidden gate in that research roadblock; for this, we need a special kind of test.
While most companies selling direct-to-consumer DNA kits for genealogy provide what is called an autosomal test, there are two other types of tests which can boost our progress beyond those research roadblocks. One, the more familiar of the two tests, is known as the Y-DNA test. That test reveals what is called a man's patriline—his father's father's father's paternal ancestry. The other test, though not as widely utilized, is called the mitochondrial DNA test, or mtDNA for short.
As you may have guessed, the mtDNA test can reveal the test-taker's mother's mother's mother's maternal line. Unlike the Y-DNA test, which can only be taken by men, all of us inherit mtDNA from our mother's matriline (though only women pass this type of DNA along to their children).
What is most useful about the mtDNA test is the rate at which the mtDNA itself mutates, or changes over generations. Clue: molasses in January is the speed of light, compared to mtDNA mutations. Or, as the ISOGG wiki has noted, if two people who have taken the full mtDNA test (the most complete version) are an exact match, that means the most recent common ancestor they share could be as distant as twenty two generations, or up to 550 years ago. Even if you were descended from well-documented royalty, you'd likely be hard pressed to come up with a paper trail of your ancestors reaching back that far.
I had already used the mtDNA test on a puzzle in my own family tree, a second great-grandmother who was raised as an orphan. An exact match to my full-sequence mtDNA test revealed a most recent common ancestor we shared who was born in 1700. While that was not exactly 550 years ago, it was about as far as I could have stretched my paper trail—if I even knew which direction to take my research.
As it turns out, my research goal for this month—learning more about Elizabeth Howard, the mother of Sarah Howard Ijams—puts us squarely on the matriline for my mother-in-law. Elizabeth Howard would be her fourth great-grandmother, a real stretch if we had to rely on autosomal DNA matches to press forward another generation to Elizabeth's parents. But for mtDNA, even Elizabeth's likely birth in the 1750s might not cause us any problems.
The only problem we'd have would be if there were no exact matches for my mother-in-law's matriline. But even though my mother-in-law died a few years before I became involved in using genetic genealogy, fortunately all her children—both daughters and sons—would carry the same mtDNA, most likely unmutated.
One of her sons, my husband, did indeed take that test, and so far has four mtDNA matches, three of whom are exact matches. While none of those matches' names show up in her extensive family tree, a month of dedicated attention to this research question may provide us with some leads. We'll touch base with this supporting research question as we work our way through the upcoming month's research goal.