Phenotypic divergence between Oryza rufipogon and O. nivara based on 18 quantitative traits recorded in the common garden experiment. (a) Divergence in mean phenotypic values of the combined samples. The species differences were standardized to the smaller value of the two species and thus the scale represents the relative difference between species for individual traits. (b) Significance (after correction for multiple testing) and direction of phenotypic divergence in six population pairs of O. rufipogon and O. nivara. Parentheses indicate that the direction of phenotypic divergence was opposite to that found in the combined samples.