Pneumonia epizootics appear to be driven by density-dependence, serving to constrain population size [ 5], and presumably selecting for the most fit genotypes.
For Manus, North Fiji, and Lau Basin samples of Ifremeria nautilei, estimates of effective population size using either microsatellite linkage disequilibrium or coalescent analysis could not constrain population sizes among basins, suggesting that within each basin, effective population size is functionally infinite.
However, pneumonia epizootics appear to be driven by density-dependence, and thus disease may constrain population growth and size [ 5].
We further advocate that restricted gene flow, together with within-population assortative mating, now constrains effective population sizes, accelerating the decrease in genetic variance due to drift.
In addition to a null model that constrained the effective population size in donor (N D ) and recipient (N R ) to be identical (so that there is no bottleneck at transmission), models with constant, exponential and logistic demographic functions for the recipient population were fitted.
The in-silico populations were then constrained to a constant population size of 3,000 and experienced random sexual reproduction for 100 generations with no migration and no mutation.
While population size necessarily constrains the adaptive potential and the dynamics of adaptation, theoretical results suggest that selection within small populations can increase the rate of fixation of advantageous mutations [ 59, 60].
This suggests that caution must be applied before utilizing θ, θ0, or other dimensionless gene transfer parameters, to estimate an effective gene transfer rate without additional information that constrains the estimates of both population size and growth rate.
Individuals' home ranges are constrained by resource distribution and density, population size, and energetic requirements.
Since the population size is not constrained, this simulation method includes a stochastic analogue of the Lotka-Volterra cycles.
In real biological communities, the efficacy of innate and adaptive immune systems is constrained by ecological factors such as population size, structure and diversity.
