10.5061/DRYAD.7M2R4
Myhre, Ane Marlene
Norwegian University of Science and Technology
Engen, Steinar
Norwegian University of Science and Technology
Sæther, Bernt-Erik
Norwegian University of Science and Technology
SAEther, B.-E.
Norwegian University of Science and Technology
Data from: Effective size in density-dependent two-sex populations: the
effect of mating systems
Dryad
dataset
2017
sex ratio fluctuations
Fluctuating Populations
Demographic Stochasticity
Mating Systems
2017-06-19T15:52:58Z
2017-06-19T15:52:58Z
en
https://doi.org/10.1111/jeb.13126
31203 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Density dependence in vital rates is a key feature affecting temporal
fluctuations of natural populations. This has important implications for
the rate of random genetic drift. Mating systems also greatly affect
effective population sizes, but knowledge of how mating system and density
regulation interact to affect random genetic drift is poor. Using
theoretical models and simulations, we compare Ne in short-lived, density
dependent animal populations with different mating systems. We study the
impact of a fluctuating, density dependent sex ratio and consider both a
stable and a fluctuating environment. We find a negative relationship
between annual Ne/N and adult population size N due to density dependence,
suggesting that loss of genetic variation is reduced at small densities.
The magnitude of this decrease was affected by mating system and life
history. A male-biased, density dependent sex ratio reduces the rate of
genetic drift compared to an equal, density independent sex ratio, but a
stochastic change towards male-bias reduces the Ne/N ratio. Environmental
stochasticity amplifies temporal fluctuations in population size, and is
thus vital to consider in estimation of effective population sizes over
longer time periods. Our results on the reduced loss of genetic variation
at small densities, particularly in polygamous populations, indicate that
density regulation may facilitate adaptive evolution at small population
sizes.
R-codeIncludes the functions used to generate simulated data of genetic
drift. Feeding this function with the parameters provided in the article
and following the same procedure will provide similar results.R-Code.R