Millions and Billions of Ancestors
In his article entitled, “Everyone is Descended from Millions, make that Billions, of Ancestors” Dan Eastman states: "After all, you have two parents, four grandparents, eight great-grandparents, sixteen great-great-grandparents, and so on in a straight mathematical progression. If you go back 300 years, you have about 4,000 ancestors, assuming no duplicates. If you go back a thousand years, and each of us theoretically has more than a trillion direct ancestors, again assuming no duplicates. Of course, all of us have duplicates." This is a very interesting article, go read it at Eastman’s Online Genealogy Newsletter here Source: Eastman, Richard W, Eastman’s Online Genealogy Newsletter, dated 30 July 2012, published online. http://blog.eogn.com/eastmans_online_genealogy/2012/07/everyone-is-descended-from-millions-make-that-billions-of-ancestors.html