The Wikipedia page for Paraguay states:
"The normal estimate is that of a Paraguayan population of somewhere between 450,000 and 900,000, only 220,000 survived the war, of whom only 28,000 were adult males."
Yet today, the gender ratio for Paraguay indicates a slighter higher number of males to females. Considering that only 150 years have passed and unless I am misunderstanding this, how did the gender ratio of the country make such a quick recovery?
I'm not sure this is really a history question. The gender ratio at a given moment has no bearing on the gender ratio of children born at that time. So once that generation has died, all other things being equal, the population should have a normal gender distribution again, even if the population will likely have reduced significantly relative to the previous generation.