Ancestry DNA Origins

Four Tests, Four Maps

Have you looked at the Origins map for your AncestryDNA test? Have you compared your map with those of other family members?

I've had my DNA tested with Ancestry, as have my mother and my two brothers. While I've spent considerable time working with our DNA matches, I haven't paid nearly as much attention to the Origins information.

Why? Because most of my genealogy research is focused on ancestors who lived in the United States. Although I have identified a few immigrant ancestors, many of my family lines are still firmly rooted in American records, with their European origins unknown.

Recently, I decided to take another look at our AncestryDNA Origins results.

Four DNA Tests

Having DNA results for my mother and all three of her children provides an interesting opportunity to compare our estimated geographic origins.

AncestryDNA analyzes our DNA and compares it with reference populations to estimate the geographic regions associated with our ancestry. These estimates are presented as percentages and displayed on maps.

Since children inherit approximately half of their autosomal DNA from each parent, one might expect the Origins maps of three siblings to be quite similar.

But are they?

My Mother's Origins

My mother's results provide a starting point for comparing the three siblings. Her map identifies regions in the British Isles and continental Europe.

Since she is one generation closer to our shared ancestors, her DNA also provides information that may not be represented in the DNA inherited by any one of her children.

My Origins — MC

My Origins map shares many geographic regions with my mother's map. However, there are also differences.

Some regions appearing in her results do not appear in mine. My map also includes regions that are not identified in hers.

Of course, half of my DNA came from my father, which helps explain why my results are not identical to my mother's.

My Brother DC's Origins

My brother DC inherited a different combination of DNA from our parents.

Although his Origins map shares many regions with mine, there are differences in the geographic areas identified and in their estimated percentages.

My Brother TC's Origins

My brother TC's map provides a fourth perspective on our family's ancestry.

Like DC and me, he inherited approximately half of his DNA from each parent. However, the particular segments he inherited are not identical to those inherited by either of his siblings.

Comparing the Maps

When I first looked at these four maps, I expected differences between my mother's results and those of her children. After all, each of us inherited DNA from our father as well.

What caught my attention was the variation among the three siblings.

We have the same parents, yet Ancestry identifies somewhat different geographic origins for each of us.

I was also intrigued by the regions identified in my mother's DNA that do not appear in any of her children's Origins estimates.

Does that mean none of us inherited DNA associated with those regions? Or is Ancestry interpreting some of our inherited DNA differently?

Those questions led me to examine the Origins percentages more closely, including Ancestry's estimates of which regions were inherited from our mother and which came from our father.

What Can These Maps Tell Us?

AncestryDNA Origins maps are fascinating, but they are not the same as a documented family tree.

They represent estimates based on comparisons with reference populations. As Ancestry updates its reference data and methods, the geographic regions and percentages can change.

For that reason, I have never considered these maps proof that a particular ancestor came from a specific country or region.

However, comparing the results of four closely related people raises some interesting questions about genetic inheritance and the way Ancestry identifies geographic origins.

In my next post, I'll take a closer look at the percentages behind these maps, compare the maternal and paternal contributions to the three siblings, and consider how the results relate to what I know about my family's immigrant ancestors.

Have you compared your AncestryDNA Origins map with those of your parents or siblings? Did you find any unexpected differences?