I had 4 grandparents and 8 great grand parents. Following this logic I had 2 to power 80 ancestors in Roman !?

Question

In Roman times. That calculates at many trillion! But that isn't possible since best estimates put world popn. at a few 100 million at that time. I realise that there will be some 'double counting' in this approx calculation but does this account for the difference? Dont forget that was just my ancestors -- What about yours and yours ---------------? Come on you mathematicians there must be a (simple?) answer.

Answer 1

I've read somewhere that all mankind actually descends from a very small group of common ancestors which included as few as 4 females.This conclusion resulted from DNA studies to which mathematics were applied.We all have common ancestors,more or less.Hello,cousin!

Answer 2

As others have said, people married their cousins. Where my Pack ancestors came from, in what is now Monroe County WV, if you wanted to marry a woman of your own race it was a cousin or nothing. The slaves got a little additions or subtraction to the gene pool when someone bought or sold one through a travelling slave dealer, but neither white nor black people went away to the big city to find a job or go to college. They usually lived their lives within 20 - 30 miles of where they were born and married someone they'd known all their life, who was usually a cousin of some sort.

Answer 3

You, your brothers and sisters, your cousins also had 4 grandparents, 2 of which you share. And so it goes on up the tree with plenty of overlaps.
A few hundred million is still plenty enough to provide a healthy gene pool, but it may well be true that you are related to far more people than you realize!

Answer 4

well..your also forgetting that the average life span back then was about 1/2 or less of what it is today because of modern day medicine. So because of a longer life span. There will be more people at once on this earth. So your calculations could actually be pretty accurate if they lived as long as we do today.

Answer 5

Double counting, people marrying in the same family and having a large offspring, sharing the same ancestors.

Answer 6

You may forget that a lot of people back then and even up until the 1800s married cousins. I know it sounds funny but, the family tree didn't always fork lol.

Answer 7

large family back in the old day people had more children.
People are related to other people if they research their family tree far enough. Some man had two wives.
Wars and disease and nature cut the population down to.

Answer 8

Naturally u have 4 grandpas, and 8 g.grandpa's, What is there logic. ( 2 g.ps of your father & 2 g.ps of your mother. they have their paratens like this.

Answer 9

TRULY TERRIBLE!