THE EVOLUTION OF REPRODUCTIVE EFFORT IN LIZARDS AND SNAKES.

摘要: Life history theory suggests that the optimal evolved level of reproductive effort (RE) for an organism depends upon degree to which additional current investment reduces future output. Future reproduction can be decreased in two ways, through (i) decreases organism's survival rate, and/or (ii) growth (and hence subsequent fecundity). The latter tradeoff-that is, "potential fecundity cost"-should affect evolution RE only species with relatively high a rate increase body size, or frequency per annum. Unless these conditions are met, probable benefit obtained from decreasing present output is too low natural selection favor any reduction below maximum physiologically possible. Published data on and relative clutch mass (RCM) suggest many lizard fall well at expected influence such fecundity" tradeoffs. Hence, allocation resources between unlikely directly optimized by animals. Instead, energy should indirectly, via effects probability during reproduction. Survival costs may most important evolutionary determinants reptiles, information nature extent needed before valid measures reptilian constructed.