To what extent can variation in human microsatellite length be predicted by demographically induced variation in heterozygosity and allele length skew after full phylogenetic correction?. Repeat of the analysis presented in Figure 2 above, but this time with full correction for possible phylogenetic non-independence using the method of independent contrasts . Briefly, the input data are replaced with absolute differences in trait value between the N-1 taxon pairs that share a common node, where N is the number of populations (53). Figure 3a: number of models achieving a given level of significance for the full models (black bars) and for dropping skew (grey bars), population size (white bars) or distance + distance2 (striped bars). Values on the X axis refer to lower bin boundary; i.e. '1' indicates non-significant models with P > 0.05, '0.05' indicates models with P-values lying between 0.05 and 0.01. Figure 3b: number of models explaining a given proportion of the null deviance. Colour coding of the bars is the same as in Figure 3a but X axis values are upper bin boundaries.