Around the early 1800s there were 128 random strangers on Earth, each of whose genes makes up 1/128 of you. Some prob. knew each other and had no idea they& #39;d share a common descendant. There are 127 critical sex moments in this chart. If just 1 doesn& #39;t happen you never exist. 1/5

Of course if you keep going, things quickly get hectic. In the mid-1600s, you& #39;ve got over 4,000 ancestors roaming the Earth. Some of them probably fucking hated each other. Also, now you& #39;re relying on 4,095 times people banged—if only 4,094 had happened, you wouldn& #39;t exist. 2/5

Keep going with this and you reach a weird contradiction. How is this explained? "Pedigree collapse," a euphemism for a whole lot of incest. Fun fact: 80% of all people who have ever lived have been born to parents who were second cousins or closer. 3/5

Cousins gets weird too. 1st cousins share a set of grandparents. 2nd cousins share a set of great-grandparents. And so on. This number quickly balloons out, esp when people have a lot of kids. Everyone on Earth is 50th cousins or closer. We really are all one big family 4/5

Full post here: https://waitbutwhy.com/2014/01/your-family-past-present-and-future.html">https://waitbutwhy.com/2014/01/y... 5/5