You’re Descended from Royalty and So Is Everybody Else
I read something while researching my DNA results that made me realize how little my ancestors have to do with me.  Maybe somebody here can tell me if it's actually true.<p>You share about 0.5^n percent of your DNA with each member of generation n, where n = 1 are your parents, n = 2 your grandparents, and so on.  The explanation that was given to me is that each of your parents contributes 50% to your genes.  Depending on which of their parents' genes they gave you, you share anywhere from 0 to 50% of your DNA with each of your grandparents, but for simplicity's sake let's call it 25%.<p>The point is, most of the people we're trying to find out more about through ancestry websites and DNA tests are barely related to you.  Searching for your great, great, great grandfather from the old country?  Fine, you only share about 3% of your DNA with him.