Table 1. Percent sequence variation within and between Capsella spp.

		C. rubella
	C. grandiflora	Greek	Out-of-Greece	All
C. grandiflora	1.86 [1.83,1.93]
Greek C. rubella	2.03 [2.01,2.13]	0.40 [0.39,0.45]
Out-of-Greece C. rubella	2.02 [2.00,2.09]	0.46 [0.45,0.52]	0.27 [0.26,0.32]
All C. rubella	2.03 [2.00,2.11]	NA	NA	0.41 [0.40,0.46]

Neutral variation within and between Capsella populations. Percent sequence differences at synonymous sites averaged across pairs of individuals within and between C. rubella and C. grandiflora. This matrix is symmetric and comparisons between partially overlapping sets (e.g.C. rubella x Greek C. rubella) are noted as ‘NA’. Redundant cells above the main diagonal are intentionally left blank.