ISSN:
1573-8477
Keywords:
age-structured population dynamics
;
ESS
;
age at maturity
;
size-dependent mortality
;
freshwater clams
;
predation
;
castrating parasitism
;
stochasticity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We studied the evolution of age at maturity in freshwater clams of the genus Anodonta in relation to their ecology. We analysed an age-structured density-dependent population dynamics model, which we developed for freshwater clams, using several different options for density dependence. As evolutionary optimality criteria we applied both the maximization of a fitness measure (either intrinsic rate of increase or expected lifetime fecundity) and the concept of evolutionarily stable strategies (ESSs). All three evolutionary criteria yielded estimates which were too high for the optimal age at maturity in a deterministic model with a constant survival rate. The predictions are improved when size-selective predation is included in the model. Mature clams also face a risk of infection by castrating parasites, which would select for delayed maturity. Variable newborn survival selects for earlier reproduction, though the observed levels of stochasticity probably have a negligible effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018435513099
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