Tim Taylor has a nice piece  about the extension of human lifespans. Mortality has, as we know, fallen dramatically (or lifespans have extended, same thing) since the hunter gatherer days. We all know they exercised regularly, had no chemicals, little pollution and ate organic food. And were all dead by 35. We have all of the chemicals, lots of pollution, eat polluted chemical muck and live into our late 70s. But here's the fascinating fact:
The bulk of this mortality reduction has occurred since 1900 and has been experienced by only about 4 of the roughly 8,000 human generations that have ever lived.
This life extension has not been evenly distributed over time. The two countries studied are Sweden and Japan and they really only climbed on board this capitalism, markets and industrialisation train at around and about 1900. There's a very clear link between the two therefore.
That is, Swedes in 1900 had mortality profiles closer to hunter-gatherers than to the Swedes of today. This relative difference between Swedes recently and those 100 y ago has emerged in a rapid revolutionary leap, as this distance is far greater than that between hunter-gatherers and chimps. The recent jumps in mortality reduction are remarkable in the context of mammal diversity because age-specific death rates for hunter-gatherers are already exceptionally low, probably among the lowest of any nonhuman primate or terrestrial mammal (especially if body size is controlled for), and lower than even captive chimpanzees at all ages.
Of course, I don't actually believe that a system of economic organisation has directly extended human lifespans. Not even the most miserablist Marxist would claim that we all live longer so that we've longer to be oppressed by the capitalists. However, this strange trio, the capitalism/markets/industry thing, is the only economic system that has ever produced a consistent surplus over and above subsistence for the average person. Everywhere there was economic growth before it was swallowed in Malthusian growth, in the growth of the population. And I would argue that it is the production, consistently, of that surplus that has led to the extension of lifespans.
Or if you like, an old riff of mine: the good old days are right now. We've never had it so good, we've never been as rich, worked less hard nor had so many years of life to enjoy it. Which is a pretty good result of a method of socio-economic organisation, isn't it?