Senescence is the scientific name for ageing and relates to the biological processes which take place in individuals at older ages.

A number of scientific theories exist for what causes ageing. Under ‘Medawaran’ school of thought, ageing is the result of cellular damage and mutations. Another theory (‘pleiotropy’) suggests that genes which are favourable in early life (and so to survival to reproductive years) may have detrimental effects in older. Both of these theories are based on evolutionary principlesevolution will favour characteristics which lead to successful reproduction and so continuation of the species even if these are detrimental in post reproductive years.

An alternative view on the ageing process is given by reliability theory which derives from mechanics: the failure of too many parts of an organism eventually leads to death.

In recent years considerable research has been undertaken to further our scientific understanding of ageing. Indeed some scientists believe that by using specific medical interventions and strategies it is possible to engineer considerable slowing of the process of ageing leading to claims that it may be possible to live to well in excess of 100.