The Math of Ancestry

 The basic fact is that we’re all related. An article that I read claimed that everyone on the planet today is within 16^th cousins (genetically) at the furthest relationship. Some debate the accuracy of that argument, but the overall fact that we are all distantly related remains. So, the question really becomes how distant is the relationship and are you related to some individuals multiple times? The more family that you input into your family tree, the more likely you’ll see that you are related to some people multiple times. If you only entered yourself, parents and grandparents going back to your 12^th great-grandparents (if you could locate all of them) into your family tree you would have 33,367 people.  

When you look at the math of ancestry it makes sense that you trace your roots back to some of the same characters. Since you have over four-thousand 10^th great-grandparents, it’s realistic to consider that some of those are the same. Some might be disheartened and question the point of doing ancestry research if we are all related, but even though we know we are related, the discovery is in how we are related.  

Grandparents                                      4

Great-Grandparents                            8

Great-Great Grandparents                  16

Third Great-Grandparents                  32

Fourth Great-Grandparents                64

Fifth Great-Grandparents                   128

Sixth Great-Grandparents                   256

Seventh Great-Grandparents              512

Eighth Great-Grandparents                1,024

Ninth Great-Grandparents                  2,048

Tenth Great-Grandparents                  4,096

Eleventh Great-Grandparents             8,192

Twelfth Great-Grandparents              16,384 

Further Reading

Family Trees: Tracing the worlds ancestor

The Royal We

Mitochondrial Eve

Y-chromosomal Adam