I suppose you guys just made up those numbers. As has been said, modern humans only appeared 100,000-200,000 years ago. Humans living only 40 years? Life expectancy at birth comparisons are completely flawed due to the improvements made in the modern era regarding child mortality and death during childbirth. The life expectancy for someone who reaches adulthood has always been far better. Also factor in that people these days marry later and often divorce.
with legal prostitution marriage would no longer be a problem. I mean why deny it, we all know what men really want.