I must have misread you, because I thought you were writing "All it takes is one of those groups to keep having children". Well yeah, obviously as long as the

I must have misread you, because I thought you were writing "All it takes is one of those groups to keep having children". Well yeah, obviously as long as the population keeps growing [1] (and for that it is sufficient that a subgroup does indeed), there can not be a peak child. I was assuming that the article posited the existence of a population peak in the future, and was speculating about how many years would it be preceded by a child peak. 1. or rather, renew generations, since the population can grow without renewing generations.