There are differences in generation interval in different times and places.

[bicicleur 2]

https://www.nature.com/articles/s41...ok-3qyfqGIuQvG96l2byc_iXodaaKpJTd3NZmxJI-Bye4

[h=1]Different historical generation intervals in human populations inferred from Neanderthal fragment lengths and mutation signatures[/h]