Fig. 5

Simulation of the loss of genetic diversity over 100 years in the introduced population. The top panels show changes in the mean allele number per locus (Na) at various population growth rates (λ) when the founder population size = 20, 40, 60, or 80 individuals, and the horizontal dashed lines indicate the observed Na in the current Beijing population (~ 90 years post introduction). The bottom panels show changes in population size with different founder sizes and λ while following a logistic growth pattern. The initial sex ratio in the founder population was set at female:male = 1:3. See Additional file 1: Fig. S3 for simulation results at 1:1, 1:6, and 1:9 female:male sex ratios