Variance in Female Reproductive Success Differentially Impacts Effective Population Size in the Short-Nosed Fruit Bat, Cynopterus sphinx
|Variance in Female Reproductive Success Differentially Impacts Effective Population Size in the Short-Nosed Fruit Bat, Cynopterus sphinx
|Year of Publication
|Garg KM, Ramakrishnan U
Effective population size (Ne) quantifies the effects of micro-evolutionary processes and the rate of loss of genetic diversity in a population. Several demographic and mating parameters reduce Ne. Theoretical studies elucidate the impacts of various demographic and mating system parameters on Ne, while empirical studies illustrate realized Ne for species with differing life histories and mating systems. However, effect of intra-specific variation in mating system on effective size remains largely unexplored. In this paper we investigated the effect of promiscuous and polygynous mating on Ne in two wild populations of the short-nosed fruit bat, Cynopterus sphinx. Ne/N (ratio of effective population size to census size) was lower than unity in both populations, and much lower for the polygynous population compared to promiscuous population. Elasticity analyses reveal that Ne/N was sensitive to deviations in the sex ratio. Variance in female reproductive success had a higher impact on Ne compared to variance in male reproductive success in the promiscuous population. However, for the polygynous population, impact of variance in male reproductive success on Ne was higher than that of variance in female reproductive success. Our results suggest that depending on mating system, different populations of the same species could have alternate evolutionary trajectories. The rate of loss of genetic diversity would be lower for the promiscuous population compared to the polygynous population. Our study is the first to highlight which parameters would most significantly impact population specific Ne under different mating systems.