Table 1.

Linear Model Testing Relationships between Genomic Diversity and Census Size, the Mating System, Ancestral Cluster, Distance to Cluster Core, and Admixture.

	Intergenic Regions				CDS Regions
	π		θ		π		θ
Source	Estimate	Var. (%)	Estimate	Var. (%)	Estimate	Var. (%)	Estimate	Var. (%)
Intercept	0.0039∗∗∗		0.0038∗∗∗		0.0010∗∗∗		0.0009∗∗∗
log10 (census size)	0.0001	0.76	0.0001	0.79	0.0000	0.72	0.0000	0.70
Mating system (selfing)	−0.0017∗∗∗	31.74	−0.0017∗∗∗	26.35	−0.0006∗∗∗	33.43	−0.0005∗∗∗	28.45
Ancestral cluster (west)	−0.0008∗∗	15.65	−0.0007∗	11.69	−0.0002	9.44	−0.0001	7.76
log10 (distance to core)	−0.0026∗∗∗	26.57	−0.0031∗∗∗	27.47	−0.0010∗∗∗	29.96	−0.0010∗∗∗	30.17
Admixture (yes)	0.0006∗	1.79	0.0005	1.62	0.0002	1.71	0.0002	1.57

Genomic diversity is represented by the weighted medians of Tajima's π and Watterson's θ of intergenic regions and CDS regions (windows of 5000 bp). The sample size for all models was 52 populations. Models explained a large amount of variation: intergenic π, R² = 0.77; θ, R² = 0.68; CDS π, R² = 0.75; θ, R² = 0.69. Estimated intercept and coefficients, and variation explained are reported. Significance is indicated: ∗0.01 < P ≤ 0.05, ∗∗0.001 < P ≤ 0.01, ∗∗∗P ≤ 0.001.