It is natural to wonder at one time or another where you came from. It is not easy to get a good answer. At some age, you understand that you came from Mommy and Daddy. Uh-oh, the question arises: Where did Mommy and Daddy come from? I find it surprisingly difficult to remember my grandmother came from her mommy and daddy. All the people came from their parents, who came from their parents, and we are back to the formula 2n
That is the formula which gets very big quickly and was mentioned in the blog post for 8/18/2020. It is the formula for the total number of selections possible from any set of N items. It is also the formula for the number of ancestors I have N generations back. 2 parents, 4 grandparents, 8 greatgrandparents, etc. How far back can I go? I think the short answer is that nobody knows. Part of the problem is deciding what we mean by "parents", and by "humans". I tend to jump over the details and confess to being descended from cockroaches and algae.
About ten years ago, I paid for the services of the National Geographic Society's Genographic Project to analyze my DNA. I learned about ancestors leaving Africa, scooting generation by generation around the eatern end of the Mediterranean and moving north, north, north. Eventually, they turned south, according to this account and traveled down the west coast of Europe, dropping off cousins and settlers. My DNA markers are similar to Irish and Spanish men. The Genographic Project allowed participants to transfer one's results to the Family Tree organization. I have been getting emails from Family Tree about their finding people related to me for years.
Today, I downloaded the list of relatives they found. I read decades ago that "Kirby" was the 511th most common last name in the US. So, I knew they would find people related to me in different degrees of closeness. Today's download lists 1836 people that Family Tree has identified as related to me according to their definition of "related".
