How many ancestors does the average person living today had alive say 2,000 or 3,000 years ago?

Question

This is a question on the exponential growth of ancestors with each passing generation. The issue becomes then that with passing generations, "cross breeding" would most likely occur. Additionally, I assume that there are two or three generations alive at any one moment.

Answer 1

I saw an article recently from the associated press. It was called "Roots of Human Family Tree are Shallow". It was based on the work of a man named Steve Olsen, who has been studying human history. He worked with a statistician and a computer scientist to create a program that would trace everyone living today back to a common ancestor. They estimated that you would have to go back only 2,000 to 5,000 years to find one person who we could all count as our ancestor (because of genealogical dead-ends, and migration this would be possible).

Answer 2

Well, if you figure 20 to 25 years per generation, that's quite a long time back. But remember, it has only been a rather short time since the various gene pools were in any significant way mixed together. The earliest major mixings are lost in time, as Europe and Northern Africa collided with Asia. But until the advent of large sailing ships able to cross oceans, only a few hundred years ago, and for a slow growing time thereafter, gene pools did not mix much. So most of us come from a rather small, rather inbred group or perhaps by now the majority come from more than one such small, rather inbred group.

So we may not have anywhere near as many distant ancestors as the mathematics might imply. Before you go back very far, you start finding cousins or kins that lead ultimately to a common ancestor for the mother and father, and there you are; a small number of ancestors backwards in time after that.

Answer 3

You can't make the assumption that two ro three generations were alive at any moment, The life span 3000 years ago was only about 24 to 35 years before people died.

There is no one here that could possibly answer the question accurately.