Germans, Spaniards, Italians and Greek have upside-down family trees: four grandparents have two children and one grandchild.
#####
Steyn is a genius at making huge concepts simple to understand. I will use this whenever I try to explain what “unsustainable birth rate” means.
The corrolary to this is that, after a few generations, there's no brothers, no sisters, no aunts, no uncles and no cousins.