Adaptive Life Histories Effected by Age-Specific Survival and Growth Rate

摘要: Life history data for three unexploited populations of brook trout, Salvelinus fontinalis, were used to test the predictions life theory that, relative juveniles, (1) high adult survival favors low reproductive effort and delayed reproduction, (2) increased juvenile growth rate early reproduction. Field sup- ported both predictions. The population having highest adult-to-juvenile ratio expended least effort, reproduced latest in life, experienced lowest cost Among a juvenile-to-adult was associated with cost. Early repro- duction also within populations. adaptive significance interpopulation variation assessed by comparing fitness, r, observed histories those potentially alternative strategies. Empirically derived fitness functions supported hypothesis that differences adaptive. Observed combinations age-specific fecundity maximized fitness. Within advantages reproducing favored reduced age at reproduction fastest- growing individuals. results are consistent demonstrate empirically how can independently inter- actively influence evolution.