Comment by creatonez
10 months ago
> However as we get older, there is less selective pressure, particularly in pre-industrial times.
Note that the industrial revolution did not necessarily significantly expand how long humans live. Most people who made it to adulthood could expect to live a long life, and there was only a small increase in the maximum human age. Rather, most of the difference was a drop in child mortality.
Thus, many of the selective pressures would have remained the same. But the overall point is correct -- evolutionary fitness in older age has less selective pressure than in younger age.
This is not true. While the extremely low life expectancies are indeed mostly a result of high infant mortality, and the maximum life expectancy was comparable, people that reached adulthood still died substantially younger than today.
For example amongst english aristocracy that made it to 21, the average lifespan was early 60s for most of the period from 1200 to 1750. The average age of death of English kings from 1000 to 1600 was 48. Excavations of graves of anglo-saxon field workers from 400-1000 found none over 45, while among clergy only 5% lived past 45. For English commoners from 1200 to 1750, adult life expectancy was generally early 50s.
People did not drop dead due to old age at these younger ages. The odds of dying due to malnourishment or disease were much higher at every age range. It was very possible for someone to live into their 90s back then, it was just substantially rarer.
https://www.statista.com/statistics/1102957/life-expectancy-... https://www.sarahwoodbury.com/life-expectancy-in-the-middle-....