Evolutionary theories of ageing applied to long-lived organisms

Ageing can evolve by mutation accumulation and pleiotropy (trade-offs). The relative prevalence of these two mechanisms is important for determining t he likelihood that mechanisms of ageing are homologous in distantly related organisms, and hence the relevance of long-lived organisms to general mech anisms of ageing. Experimental work with Drosophila, examining the properti es of standing genetic variation and mutations that accumulate in real time , has provided little evidence in favour of a role for mutation accumulatio n, but considerable support for the importance of trade-offs, particularly between early fertility and the rate of ageing. Evidence for the roles of t hese two processes in the evolution of long-livedness can be derived from t he response to selection, comparative studies of life history traits and te sting for potential trade-offs at the mechanistic level. (C) 2001 Elsevier Science Inc. All rights reserved.