Keynote lecture: an update on the what, why and how questions of ageing.

In this keynote address, we briefly consider three global questions on the biology of ageing. What is it? While it is certainly the case that development has a major impact upon ageing, gerontologists characterize ageing as gradual, insidious, post-maturational declines in the structure and function of multiple organ systems, certainly to include reproduction. This is accompanied by increasing rates of mortality within populations. Comprehensive, longitudinal physiological assessments are not commonly pursued in their experiments, however; this deficiency limits one's ability to interpret the results of putative interventions. Why does it happen? Although subject to recent challenges, the most satisfying explanation for inter-specific variations in longevity is given by the evolutionary biological theory of ageing. Life history parameters, including longevity, are molded by the ecological forces in which the species evolves. How does it happen? To gain insight into fundamental mechanisms of ageing, we have focused upon classes of gene actions that, according to the evolutionary theory, can escape the forces of natural selection.