The huge jump in average life expectancy has most been the result of babies living to 5 years as apposed to 70 year olds hitting 80. Paradoxically your more likely to see a living great great grandparent 300 years ago than now because people are having children later in life and the increase in 80 year old today has a lot to due with a population boom that happened over that time period.
Not that things are not far better now than at any point in the past, just life expectancy is a poor proxy for ratio of 15 year olds that reach 80. And you have 16 great great grandparent's who all lived to be old enough to have children.
Not that things are not far better now than at any point in the past, just life expectancy is a poor proxy for ratio of 15 year olds that reach 80. And you have 16 great great grandparent's who all lived to be old enough to have children.