The law of nativeness, or truncation or reduction of ancestors, etc., Eng. “Pedigree collapse”, German. “Ahnenschwund”
Formally, a direct family tree, a tree of human ancestors is built strictly according to geometric progression. Where the number of ancestors in each next, older generation, increases in two. You have a father and mother, they have their father and mother, these are your grandparents and so on. We get, geometric progression, parents – 2 people, grandfathers and grandmothers – 4, great-grandfathers and great-grandmothers – 8 and so on. In the twenty-first generation of every person! already more than a million, and in the thirtieth more than a billion, and in each next generation the number of ancestors doubles. This contradicts our knowledge of history and common sense; a paradox arises.
The farther into the past, the one hand we have more “cells” in the family tree. On the other hand, an ever-smaller number of actual people who lived in those distant times are completely occupied. In the first generation, in the sense that is farthest from us, only two people occupy a gigantic number of places in a tree.
So where did all these people go?
Just all people are relatives (having common ancestors). Someone to a greater extent, someone to a lesser, and to a much greater extent than people believe. Moving farther and deeper into generations, at first we find more and more the same people in the trees of different people, but then, merging crowns unite the same people inside the same tree. More and more of the same people occupy more and more different positions in the tree. That is, people are not only relatives to each other, but also relatives themselves. This is the paradox of genealogy.
Good luck in finding.