Evol Ecol Res 16: 435-439 (2014) Full PDF if your library subscribes.
Gompertz mortality, natural selection, and the ‘shape of ageing’
Eric L. Charnov
Department of Biology, The University of New Mexico, Albuquerque, New Mexico, USA
Correspondence: E.L. Charnov, Department of Biology, The University of New Mexico, Albuquerque, NM 87131, USA.
Question: Proposals for measuring the shape of ageing are dimensionless comparisons of early adult mortality (Z0) with aggregate mortality over the adult lifespan. What do the shape parameters actually measure? And how do they relate to the optimal age/size at maturity?
Methods: Dimensional analysis is applied to an adult Gompertz mortality function, Zx = Z0ec · x. R0, fitness in non-growing populations, is maximized with respect to the age at maturity, α.
Conclusions: A constant value for any ‘shape of ageing’ number among a collection of species implies that they also have the same value for the ratio of the two Gompertz parameters, c/Z0 (if mortality is Gompertz). Z0 appears in both the shape measure(s) and the formula for the optimal α; this provides a link between the rate of ageing and the criterion for the initiation of reproductive maturation. This ESS result suggests that (perhaps) Z0, external mortality rate early in adulthood, and not any mass-specific physiological rate, should determine the ageing rate.
Keywords: rate of living, maturation, fish, senescence, mortality rate
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2014 Eric L. Charnov. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.