What’s In Your DNA?

There are a number of DNA testing facilities available now, including Ancestry.com and 23andMe. My DNA profile tells me that I am mostly (58%) descended from ancestors from the British Isles. I was surprised when I first saw this as my ancestry tells me that I should be 25% Danish, as my grandmother’s parents were both from Denmark. The profile says I am 18% descended from Norwegians, not Danes. I am guessing that Denmark and Norway were part of the same kingdom hundreds of years ago, and that may explain how it is categorized.

But that got me to wondering several things. First of all, why wouldn’t you say that those of us who were born in the United States, whose parents, grandparents, great-grandparents, and so forth, were all born in the United States of America, were just garden variety Americans? What makes you native to a specific country? How many generations have to occupy the land before it is in your DNA? If you were born in California and moved to Tennessee, would you call yourself a Californian?

Here is another thing that stumps me. I was taught that you got half of your DNA from Mom and half from Dad. Clearly some people favor one parent or another in appearance, usually the one who is the same gender as they are. But when you look at the DNA profiles of relatives, such as first cousins, some of them share more DNA with you than others do. I have two first cousins who tested their DNA on the same provider that I used. I share 837 cM with one of them and only 732 with the other. They are children of my mother’s two brothers. I don’t see how this varies. I see how it gets a little more random when you have four grandparents or eight great-grandparents contributing to your DNA, but it seems like my mother should have the same genetic makeup as her brothers, other than of course the obvious male/female gene.

It seems like as confusing as this DNA testing is, it is very valuable information, and we should know more. Wouldn’t you like to know the medical implications of your DNA inheritance? I would like to see some sort of open system where results from any of these voluntary tests are compared with all providers. That would help law enforcement, of course, but also give us more clues. I think it is fascinating how they can sometimes detect someone’s missing ancestor by comparing DNA with other descendants.

What would you like DNA testing to tell you?