[Don Corleone]

If you’re lucky, you can find that long-lost relative you never knew about.

If you go back far enough, say about 20 generations, everyone is related. Two to the 20th power is a substantial number and those old world explorers were not Boy Scouts. Just my unscientific and humble opinion.

[goldstategop]

Genealogical databases only work if you’ve siblings. Being an only child sucks.

[Pollard]

There are many millions of people who can call the 101 Mayflower passengers their ancestors. That was 11-13 generations ago.

[HangnJudge]

... not Boy Scouts

Takes 2 to tango...

[<1/1,000,000th%]

My wife’s sister-in-law is my 29th cousin.

[Go_Raiders]

Fun fact:

2 to the 10th power is almost exactly 1000 (it’s 1024)
2 to the 20th is almost exactly a million (it’s 1,048,576)
2 to the 30th is almost exactly a billion (1,073,741,824)
etc.

20 generations is about 500 years. Population 500 years ago was around 550 million (Source:https://www.ecology.com/population-estimates-year-2050/)

Therefore a randomly selected person will have a 1 in 500 chance of having a common ancestor from 20 generations ago or less with another randomly selected person worldwide.

If you are of European descent you are almost certainly descended from Charlemagne (742 - 815). That’s 40 generations ago. The likelihood of a Pacific Islander or Aboriginal Australian or African or rural Chinese native or any of the indigenous peoples of the Americas being descended from Charlemagne is practically nil.

If you want a guaranteed common ancestor, you would probably need to go back 120,000 years (Source: http://blogs.discovermagazine.com/deadthings/2017/12/07/human-migration-rewrite/#.XadDfehKjIU).

That’s probably 6,000 generations or more.

2 to the 6,000th power is 1.5 x 10^1086 which is 15 followed by 1085 zeros!

[thirst4truth]

If you go back far enough, say about 20 generations, everyone is related. My brother has found the ships manifest from our family members that came from England in 1624, it has the names of all immigrant members and their childrens names. Saw the list for the first time a few months ago. The first page had the parents names and how many children, the second page had the childrens names and ages.

It listed the childrens name as John Lewis, my brothers name, next on the list John Woodward my sons name! I looked at my brother and said, The Lewis' and Woodwards came over on the same ship?

[Robert A Cook PE]

If you’re lucky, you can find that long-lost relative you never knew about.

Heck, you might even find out your are your own grandpa!