Phillip Ashmole. He suggests latitude affects fecundity due to seasonality increasing with increasing latitudes. This theory relies on the mortality concept proposed by Moreau but focuses on how seasonality affects mortality and, in turn, population densities. Thus in places with higher mortality, there is more food availability, leading to higher fecundity. Another hypothesis claims that seasonality affects fecundity due to varying lengths of breeding seasons. This idea suggests that shorter breeding seasons select a larger clutch size to compensate for the reduced reproduction frequency, thus increasing those species' fecundity. Fecundity and fitness Fecundity is a significant component of fitness. Fecundity Selection builds on that idea. This idea claims that the genetic selection of traits that increase an organism's fecundity is, in turn, advantageous to an organism's fitness. Fecundity Schedule Fecundity Schedules are data tables that display the patterns of birth amongst individuals of different ages in a population. These are typically found in life tables under the columns Fx and mx. Fx lists the total number of young produced by each age class, and mx is the mean number of young produced, found by finding the number of young produced per surviving individual. For example, if you have 12 individuals in an age class and they produced 16 surviving young, the Fx is 16, and the mx is 1.336. Additional information Additionally, social trends and societal norms may influence fecundity, though this influence tends to be temporary. Indeed, it is considered impossible to cease reproduction based on social factors, and fecundity tends to rise after a brief decline. Fecundity has also been shown to increase in ungulates with relation to warmer weather. In sexual evolutionary biology, especially in sexual selection, fecundity is contrasted to reproductivity. See also Fecundity selection Birth rate Natalism Population ecology Biological life cycle References Fertility Population Philosophy of science