In 100 BC, the average man in the most advanced society lived to 25. Over the next 2000 years, man's life expectancy grew from 25 to 45 -- a 20 year gain. Or approximately 0.03% per year. That is a significant achievement -- man has been able to overcome nature (and human nature).
But by unleashing the unbelievable developments in technology, we have massively increased out pace of growth of life expectancy since 1900. From 1900 to 2000, man's life expectancy grew from 45 to 75 -- or 30 years over the century (or approximately 0.51% per year) -- and that includes an incredibly bloody century of two world wars ... the Spanish flu ... genocides in Eastern Europe, Rwanda, Cambodia ... and more.
Quick recap -- over the last 2100 years, man's life expectancy grew from 25 to 75 -- but the rate of growth was 17 times faster during the last 100 years then during the previous 2000 years.
That said, does this mean that according to this trend that man will one day essentially live forever? Or will we soon hit a right wall through which man cannot live past (at least on average -- there will always be outliers)?
I tend to think that within the next 200 years we will see that either:
1. man will live forever
2. some mutated disease will virtually wipe man out
For many, both scenarios are quite depressing. And while most people hope the options aren't quite so binary, I'm not sure we have any more choices.
I obviously much prefer option number 1 to option number 2 -- and we might, as a collective society, need to work very hard at ensuring the "good" outcome rather then the disaster outcome.