About a year ago, I decided I wanted to know more about my genetic background. I took Ancestry.com's test and had to wait a few weeks for the results.
Here's something a lot of people don't know about DNA tests—and it's especially important for those of us who write mysteries and other stories in which these tests often feature. Each person actually has two family trees. As Family Tree Magazine and Ancestry.com explain it, a person's genealogical tree includes "every ancestor in history that had a child who had a child who had a child who ultimately led to you." But because a parent only passes half of their DNA down to each of their children (and exactly what combination of genes goes to each child is random), even people with the same genealogical tree can have different genetic trees.
For instance, my four siblings and I all have the same parents and grandparents. My brother "Z" and I look like our dad's parents, but our sister "L" looks like our maternal grandmother's family. (It's harder to say who our other brother and sister look like.) Though I'm no geneticist, I'd guess that our mom passed certain genes down to "L" that "Z" and I didn't get, while our dad likely gave "Z" and me some genes that "L" didn't get.
Knowing all this, I expected a few surprises in the results of my DNA test. And I got some—but not the ones I'd expected. According to my ethnicity estimate, not one of my genetic markers comes from outside of Europe. I know I have at least one Native American ancestor in my genealogical tree, but apparently none of their DNA made it down to me. Furthermore, some of my genetic markers are from areas that I hadn't known were part of my family history, such as Germany.
The point I'm trying to make is that some writers treat DNA tests as magical procedures that can map out who a person is related to or where they come from with 100 percent accuracy. But it's not nearly that simple. As with any other scientific topic we might incorporate into our writing, we need to show respect for the facts and our readers by doing our research.
If you're not sure where to start with your own research, that happens to be one of my areas of expertise. Comment below about what you're struggling with so I can help you start finding the credible sources you need.
(Thanks to National Cancer Institute for sharing their work on Unsplash.)