Hey, are you my long lost tenth cousin?
March 16, 2008 6:19 PM Subscribe
What's the chance that we're related?
posted by brandnew to science & nature (17 answers total) 5 users marked this as a favorite
I had read somewhere (I forget where or the details) that researchers had determined through mathematical and Human reproductive analysis that all living Humans are likely to have had a shared ancestor that lived around 2,000 years ago. Don't quote me on the exact numbers.
I'm curious, how many years would I have to go back in order to predict that a random stranger and I have a 25% chance of a common ancestor?
OK, that last sentence was worded kind of ambiguously and confusingly); let's see if I can state it more mathematically. For any two randomly selected Humans, there is a 25% chance that they have a common ancestor within the last X years. What is X?