From In Search of Enlightenment: "Looking back over our species' history, as told in fossil records, what do we find? ... Prehistoric human remains have never revealed individuals older than about 50 years of age, and humans had a life expectancy at birth of 30 years or less for more than 99.9% of the time that we have inhabited this planet. ... So for most of our species' history there was little progress in terms of increasing life expectancy at birth. But things began to change in the 19th century. Advances in technology (e.g. the sanitation revolution), medical knowledge, material resources and changes in behaviour helped change the future course of our species. ... The fossil records of the 21st century will be unique in our species' history for two reasons. Firstly, there will be more human remains this century than in any other century (because of the size of the human population). Furthermore, the vast majority of these deaths will be caused by chronic disease and will afflict people after the age of 60. Isn't it odd, given how many people are projected to suffer and die from chronic disease and given the rapid progress that is being made in the biomedical sciences, that we don't invest more of our energies into tackling the leading cause of chronic disease? Namely, aging. When future generations look back at the 21st century they will wonder why we didn't act sooner to try to ameliorate the high risks of morbidity and mortality that currently ravage our bodies and minds."