Can’t recall where I heard it, but is there any truth to this ? :
1> Human Reproduction goes up in times of adversity (calamity/epedemics) etc. That is almost to say humans reproduce more so that the chances of survival of the kids go up.
2> Males die dispropotionately compared to females in adverse conditions. Of course calamities here exclude wars in which males are expected to die more. Calamities like say a disease outbreak, etc. are considered.