Don't Get Too Excited if a DNA Test Says You Have Ancient Royal Blood

By Kate Knibbs on at

People love finding out that they have a famous relative, or they’re descended from royalty. Thanks to genetic testing services like 23AndMe, it’s easy to send your spit away and get a rundown of your potentially regal DNA. But being related to long-ago kings doesn’t make us special—it just makes us human.

Geneticist Adam Rutherford pointed out that family trees grow backwards exponentially, so the amount of ancestors people should have from the ninth century is larger than the amount of people who were alive during the ninth century. That means anyone with European ancestry is related to King Charlemagne.

“Everyone alive in the ninth century who left descendants is the ancestor of every living European today, including Charlemagne,” Rutherford writes, explaining that Europeans alive today are probably related to the long-dead Holy Roman Emperor even if their DNA test doesn’t show it:

Because of the way the DNA deck is shuffled every time a sperm or egg is made, it doesn’t keep halving perfectly as you meander up through your family tree. If you’re fully outbred (which you aren’t), you should have 256 great-great-great-great-great-great-grandparents. But their genetic contribution to you is not equal. Before long, you will find ancestors from whom you bear no DNA. They are your family, your blood, but their genes have been diluted out of your bloodline. Even though you are directly descended from Charlemagne, you may well carry none of his DNA.

As fun as it is to find out you’re the direct descendant of an old royal line, it’s pretty meaningless.

[The Guardian]

Albrecht Dürer image via Wikimedia