23andMe, which I had analyze my DNA not so long ago, recently re-classified a tiny fraction of it from "undetermined" to "of West African origin." (99.6 percent was termed "Northern European," no surprise.) Specifically, "less than or equal to 0.01 percent" of my DNA is traceable to West Africa.
You have to go back at least 14 generations to get that kind of percentage -- say to the early to mid-1600s. Fourteen generations means more than 16,000 ancestors. (Probably less in actuality, since for most of history folks never ventured farther from their villages than 20 miles and thus inevitably married distant cousins. Certainly less in my case, since -- scandal in the family -- two of my great-great-grandparents were first cousins, it being rather lonely out on the Indiana prairie in the mid-1800s.)
How cool is this? What a great mystery. Who was this African? A slave girl at a Virginia plantation? A freebooter on some Caribbean pirate ship? The son of a West African chief sent to London to get an education? (I just read the other day that this was fairly common.) I'd love to solve the mystery, though I'm sure it's next to impossible. One just has to let the imagination roam.
I've learned quite a bit about some of my ancestors in the last decade, thanks to the Internet and Ancestry.com. I found out about the life of my mother's father, though he had disappeared from view since the 1930s. Recently a distant cousin in Norway got in touch and provided even more info on my father's side of the family. But this snippet is something I would never have known without the DNA analysis.
In my more pretentious moments, I like to point out that we are all Africans, since all of us whose ancestors later called Europe or Asia home are descended from the same small group of individuals who left Africa some 50,000 or 60,000 years ago. Finding out that I have a more recent connection with sub-Saharan Africa just makes the point more solidly that humanity is just one large, genetically mashed-up extended family.