Table 2: Environmental factors determining the genetic structure of populations. (a) Sum of posterior probabilities of models including a given factor. (b) Posterior probability of the 8 models considered. The best model is indicated in bold. (c) Estimates of the regression parameters for the best model (mean value and lower and upper limits of the 95% highest probability density interval are indicated).

Lineage transect Habitat transect Combined transect (a) Connectivity (G1) 0.069 0.107 0.081 Environment (G2) 0.070 0.184 0.458 Lineage/habitat (G3) 0.079 0.228 0.572 (b) Constant 0.800 0.554 0.068 Constant, G1 0.057 0.067 0.012 Constant, G2 0.058 0.134 0.319 Constant, G3 0.006 0.175 0.431 Constant, G1, G2 0.067 0.017 0.029 Constant, G1, G3 0.006 0.020 0.031 Constant, G2, G3 0.006 0.030 0.100 Constant, G1, G2, G3 0.001 0.003 0.010 (c) α0 α1 σ2