Family Tree?

Question

I heard something on talk radio a while back.
It seemed rather intriguing at the time.
I messed with it, but that's about it.

If you calculate it out, assuming a birth every 25 years.
Then number grows by 2^N.
Assuming that is if there was no deviance.
2^1 = 2 Your parents (25 years)
2^2 =4 Your grandparents (50 Years)
2^3 = 8 Your Great Granparents (75 years)
2^4 = 16 (100 Years)
2^? = Big Number (2000 Years) And that is just since the birth of Jesus.
If you brought the birth age down to 20, the number would be even bigger.

Does anybody know of the theory behind it?
Just how closely we are all related?
The website that talks about it?

She's doing alright. Wasn't doing all that well after brother Bob divorced her.

2^80.
80 Generations.

You would have to add up all the parents for 2000 years.

2000/25 = 80
2^80 = 1.209 x 10^24 (Really big number)
And that is only 2000 years.
3000/25 = 120
2^120 = 1.329 x 10^36 (Even bigger number)

That amount is almost an impossibility.
So, with less than that to begin with, we have created 6 billion people.

And that is calculated with people having children at 25, which is conservative.

Answer 1

I heard this story on NPR a couple of years ago. Give it a listen, maybe do a little more internet searching if it interests you.

Answer 2

This is quite interesting!

I'm sure there is logic in it - I like working with numbers, especially if they have meaning. Most of the time they do have meaning. In your analysis you have the following ;

2^1 = 2 Your parents (25 years)
2^2 =4 Your grandparents (50 Years)
2^3 = 8 Your Great Grandparents (75 years)
2^4 = 16 (100 Years)
2^? = Big Number

What do the numbers after the = sign mean? That is 2, 4, 8, 16 and Big Number stand for what?