Using DNA to Bust Genealogy Brick Walls

Blaine Bettinger, a professional genealogist specializing in DNA evidence, was a featured speaker during the Identity Quest Virtual Conference. He presented four sessions focused on DNA research in genealogy work. All of his sessions were informative, but one session in particular gave me a glimmer of hope that a “brick wall” I've had in my own genealogy research might be ready to crumble.

Bettinger talked about using Y-DNA and mtDNA (mitochondrial DNA) to explore your ancestry. The most popular ancestry DNA kits on the market right now test autosomal DNA, which is the DNA shared with all related people. Y-DNA, on the other hand, is only passed down by males (patrilineal). The mtDNA is carried by everyone but only passed down by females (matrilineal).

Why Test Y-DNA or mtDNA?

How can testing based on Y-DNA or mtDNA, the sex chromosomes, help solve genealogy puzzles that standard DNA tests can't? The trick is in how these genes are passed down from one generation to the next. Unlike autosomes, which contain a mix of the DNA from both of your parents, the sex chromosomes are passed intact from one generation to the next. That means my mtDNA is the same as my mom's and her mom';s and her mom's. This would be the case for 10 generations or more.

Finding Your Female Ancestors

One of the reasons for taking an mtDNA test is to trace a female ancestor with unknown ethnicity. The story of my father's grandma, who he affectionately knew as “Little Grandma,” has been mostly lost to history. When she died and my great grandpa remarried she was never talked about again. I've been told this happened because she was Native American and the family didn't approve of their marriage. Although my own mtDNA will not provide the answers I need, by finding a female first cousin of my father's, whose mtDNA would track perfectly through “Little Grandma’s” mtDNA line, I should be able to finally connect the dots in that branch of my family tree.

Get Started Today

Both Y-DNA and mtDNA can help solve these kinds of history mysteries. These tests can also help trace adoptee family lines, solve general genealogy brick walls, and create a record of your direct maternal and paternal lines. We have many books on genetic genealogy to get you started on your own journey.