If You have 2 parents, 4 grandparents, 8 great parents, so if you go back 40 generations you’d have a supposed 1 Trillion ancestors, But only 100B humans have ever existed. Explain.

Question

If You have 2 parents, 4 grandparents, 8 great parents, so if you go back 40 generations you’d have a supposed 1 Trillion ancestors, But only 100B humans have ever existed. Explain.

In: Biology

Answer 1

One word – interbreeding.

The further you go back the more common ancestors you’ll find between any two random people.