God has surprised us many times! In this case, one could claim that God could arrange it so that Adam was the MRCA, which bumps up everything substantially. But if one is going to claim divine intervention to arrange a perfect MRCA, then all bets are off anyway, aren’t they?[quote=“gbrooks9, post:117, topic:37034”]
These dates are estimates based on culture and technology?
[/quote]
There are a lot of assumptions built into the model, of course. I think Rohde did yeoman’s work in building it, but he lays out numerous qualifications, especially on the migration numbers. Their lifespan was a problem, too, being based on early 20th-century figures (51.4 median age at death, as I recall). Median lifespans began to climb in the 20th century. Rohde should’ve chosen something from the 19th century, at the latest. (Median lifespans were fairly steady from antiquity until the 20th century. We take it for granted these days that we should live to at least 70.) A function of the math that I frankly don’t completely understand is that the MRCA fluctuated mainly with migration and wasn’t affected too much by other factors, but the IAP seemed to be affected by every variable. At least, that’s how I read it. Maybe someone with more math skills than me can decipher the prose …
Edit: I meant migration numbers, not patterns.