• arctanthrope@lemmy.world
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      11 hours ago

      yeah, it’s about 28 generations ago, if we assume a generation to be about 25 years, where the number of ancestors you would need to have for a family tree without overlaps becomes more than the number of people alive on earth at the time. 228 is roughly the number of people alive on earth in the year 1326, which is 28×25 years ago. that’s the theoretical limit of how far back you can go without someone fucking their cousin of some degree, and it requires an exceptionally well-traveled family

      • Cethin@lemmy.zip
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        3 hours ago

        In reality, usually it’s staying inside of a small village of maybe a few hundred. Easily within 10 generations, the entire village is related.

    • Get_Off_My_WLAN@fedia.io
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      14 hours ago

      Reminds me of when I played Fallout Shelter, I made a spreadsheet to keep track of all my vault dwellers’ families.

      With the population of a tiny town, it did not take very long at all for the whole vault to become one clan.

      • fascicle@leminal.space
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        12 hours ago

        I kept one dude and like 5 women in the family room to populate the entire vault, then I would kick out people that didn’t have the same last name and then eventually kicked out all the males so it was just a 200 dweller vault of sisters

      • porous_grey_matter@lemmy.ml
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        12 hours ago

        At some point back you are (probably) related to every living thing on earth, and at the very least every animal and plant and fungus.

        • Elting@piefed.social
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          11 hours ago

          The only exception would be if life had evolved more than once on earth, which is totally possible but we would probably be able to tell.

          • porous_grey_matter@lemmy.ml
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            11 hours ago

            Yeah. From what I recall from uni classes on this ten years ago (so we might well know more now) that couldn’t be totally ruled out for the very earliest forms of life but we are as certain as we could be about bacteria just being one tree, and likewise for archaea&eukaryotes.