So, figure 25-year generations (probably too long, but this is a Fermi estimate at best), so humanity began 12000 generations ago. If you assume no consanguinity (definitely false), going backward in time each generation has twice as many of your ancestors as the previous (in counting, next in time) generation.
There have not been 2^12000 people at any point in history, or even in the sum of history. Which means we need to add some complexity. Probably a LOT of merges in that family tree (meaning it’s a family directed graph, not a tree :). Far enough back, it probably stabilizes at a few hundred each generation (meaning: effectively all pairings are (perhaps distant) cousins, so ancestors are multiply-pathed and not added at each generation). But that’s likely too constrictive. You get to make a modeling choice how you want to calculate that expansion.
And that modeling choice overwhelms most of the rest. So you have to figure out what elements are important to get right, and what expected experience you’re trying to predict. How will this bet resolve? What will happen if you’re closer to correct, vs further?
In my world, where nobody cares about the answer, but I get meaningless points for sounding smart, I’ll either refuse to answer (as above), or be super-simple and say “ancestor “width” probably stabilizes at some point less than a few thousand years back, so this is likely close to “how long was humanity mostly farmers vs mostly non-farmers”. Which is roughly 1⁄25 of the total human existence.
So, figure 25-year generations (probably too long, but this is a Fermi estimate at best), so humanity began 12000 generations ago. If you assume no consanguinity (definitely false), going backward in time each generation has twice as many of your ancestors as the previous (in counting, next in time) generation.
There have not been 2^12000 people at any point in history, or even in the sum of history. Which means we need to add some complexity. Probably a LOT of merges in that family tree (meaning it’s a family directed graph, not a tree :). Far enough back, it probably stabilizes at a few hundred each generation (meaning: effectively all pairings are (perhaps distant) cousins, so ancestors are multiply-pathed and not added at each generation). But that’s likely too constrictive. You get to make a modeling choice how you want to calculate that expansion.
And that modeling choice overwhelms most of the rest. So you have to figure out what elements are important to get right, and what expected experience you’re trying to predict. How will this bet resolve? What will happen if you’re closer to correct, vs further?
In my world, where nobody cares about the answer, but I get meaningless points for sounding smart, I’ll either refuse to answer (as above), or be super-simple and say “ancestor “width” probably stabilizes at some point less than a few thousand years back, so this is likely close to “how long was humanity mostly farmers vs mostly non-farmers”. Which is roughly 1⁄25 of the total human existence.