Table 2. Estimates of mean nucleotide diversity.

	Arabidopsis lyrata		Arabidopsis halleri
	Resistance Genes	Reference Genes	Resistance Genes	Reference Genes
πs	0.035 (0.025–0.045)	0.026 (0.020–0.032)	0.043 (0.036–0.051)	0.024 (0.018–0.030)
πa	0.014 (0.006–0.023)	0.004 (0.003–0.005)	0.008 (0.005–0.011)	0.003 (0.0025–0.005)
πtotal	0.018 (0.011–0.027)	0.010 (0.008–0.012)	0.016 (0.014–0.019)	0.008 (0.006–0.010)
Rm per site	0.007 (0.004–0.009)	0.004 (0.003–0.006)	0.004 (0.002–0.007)	0.004 (0.003–0.006)

Estimates of mean nucleotide diversity (95% C.I.s) for nonsynonymous (π_s), synonymous (π_a), and all sites (π_total) (Nei and Li 1979). R_m is the minimum number of recombination events per site (Librado and Rozas 2009).