prozema
Joined: Oct 24, 2016
• Posts: 105
June 16th, 2017 at 6:55:07 PM permalink
Sometimes random thoughts pop into my head. Here is one that disturbed me a bit.

- all people have two parents.
- so 2 parents, 4 grandparents, 8 great grandparents, and the pattern continues
- so I can calculate my total number of ancestors using algebra. 2^X (two to the x power) where X is the number of generations.

So if I assume generations are 30 years apart and I wanted to go back 1,500 years, I could calculate my number of ancestors by 2^50. (two to the 50th power). That's over 1,000,000,000,000,000 people.

The problem with that is there were not that many people on Earth then (or now for that matter)

Kinda freaky right?!? Lots of distant cousins having kids!

If this is anywhere in the neighborhood of right, how would you calculate the probably of:

1. Any given two people being related.
2. Everyone on this board being related.

Thanks
onenickelmiracle
Joined: Jan 26, 2012
• Posts: 4828
June 16th, 2017 at 7:12:46 PM permalink
Just watched a YouTube video on this, your thoughts are correct. There are more ancestors than people ever alive. 100%. We'd need to find humans on another planet if we want new blood, that evolved independently from different shoots.
Looks like sh!t just got imaginary!
prozema
Joined: Oct 24, 2016
• Posts: 105
June 16th, 2017 at 7:19:30 PM permalink
Quote: onenickelmiracle

Just watched a YouTube video on this, your thoughts are correct. There are more ancestors than people ever alive. 100%. We'd need to find humans on another planet if we want new blood, that evolved independently from different shoots.

Maybe the question should have been what is the probably that I thought of something before someone else posted a YouTube video about it... Apparently it's pretty close to 0%

:-/
prozema
Joined: Oct 24, 2016
• Posts: 105
June 16th, 2017 at 7:27:03 PM permalink
Quote: onenickelmiracle

. 100%.

Do you mean there is a 100% chance everyone is related? If so, that doesn't feel right. I could see calculus dictating the limit is 100 percent but a limit and a probably are distinct concepts.
Doc
Joined: Feb 27, 2010
• Posts: 6320
June 16th, 2017 at 7:56:29 PM permalink
If you were to subscribe to the concept that it all started with the equivalent of Adam and Eve (even if you don't subscribe to the religious aspects), then it would indeed seem 100% likely that we are all related.
prozema
Joined: Oct 24, 2016
• Posts: 105
June 16th, 2017 at 8:22:21 PM permalink
Quote: Doc

If you were to subscribe to the concept that it all started with the equivalent of Adam and Eve (even if you don't subscribe to the religious aspects), then it would indeed seem 100% likely that we are all related.

I picked 1,500 years in an attempt to avoid creation stories / theories / religion debate. Maybe thats impossible?
billryan
Joined: Nov 2, 2009
• Posts: 2143
June 16th, 2017 at 8:44:09 PM permalink
If you go back 1500 years, you had people living in what is now Chile, people living on scattered Pacific Ocean Islands and folks living in Europe near or north of the Artic Circle. I'm pretty sure they would be more than distant cousins of each other.

Another flaw in your theory is generations back then were more like 15 years apart, not 30. Women had children as soon as they were able to. By thirty, they were grandmothers.
It's what you do and not what you say If you're not part of the future then get out of the way
prozema
Joined: Oct 24, 2016
• Posts: 105
June 16th, 2017 at 8:44:41 PM permalink
Maybe this is a spatial problem?

For example, If I live in international falls MN, there is a lower probability that I'm related to someone in Nogales Mexico relative to Winnipeg Canada.

If that's the case, highway intersection, tourism, and airport hubs, and language barriers matter.

Based on that, it might be possible that it's more likely I'm related to everyone reading this message than I am to a random person is some isolated tribe of indeginous people in the Amazon / African desert / abegerinese (sp?) / (insert another "A" word here) people?

Its counter intuitive that is more likely I'm related to a random group than another single individual...

The more I think about this, the more complex it becomes.
billryan
Joined: Nov 2, 2009
• Posts: 2143
June 16th, 2017 at 8:47:31 PM permalink
KISS!!!
It's what you do and not what you say If you're not part of the future then get out of the way
onenickelmiracle
Joined: Jan 26, 2012