While most people are distant cousins, aren...

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While most people are distant cousins, aren’t most people more closely related than tenth cousin?
Answer
Several years ago, the Almanac carried an article on the length of one’s family tree. In brief, this is what it said: According to the leading geneticists, no human being of any race can be less closely related to any other human than approximately fiftieth cousin, and most of us are a lot closer. This means that the family trees of all of us, of whatever origin or trait, must meet and merge into the one genetic tree of all humanity by the time they have spread into our ancestries for about 50 generations (and perhaps as soon as the 30th generation). Consider this: If you assume only two children to a couple (a quota actually too low to permit humanity to survive), everyone — on the average — must have 4 first cousins, 16 second cousins, probably 64 third cousins, about 250 fourth cousins, roughly 1,000 fifth cousins, and some million relatives as close as tenth cousin. If you keep extrapolating into the billions, which means extending your relatives to all humanity, the range of fiftieth cousins will still easily cover the planet.