As someone with a biology background I find the conclusions a little too general. Mortality curves are not only species specific, but particular for that environment. A curve using saltwater crocodiles or lobsters would look quite different with very high mortality for the young and limited mortality for the very old. The curve for humans can (and has) been adjusted by human action to give it a better shape - especially at extreme ages. So I think it should be emphasized that the curve is not some mathematical unalterable fact of life.