My sister sent me a text with old family photos, asking if I could name anyone. Our grandfather was born in 1898, and our family is very small, so the question didn't make much sense to me. Why would pictures of people from the 1920's mean anything to anyone today? My mother was adopted, and I'm the only one in my 'blood family' to have children, and they don't care about things like that. On their father's side there are tons of relatives, but they've never felt the need to attend huge family reunions with strangers.

And yet there are millions of people paying money to find their ancestral DNA roots. Why is that? Why does it matter?