Figure 2. Relationships between phylogenetic turnover (y-axis, in mya) and different distance measures.

a: geographic (great circle) distance, b: barrier distance, an integrated measure of geographic distance and dispersal barriers, c: environmental dissimilarity based on 31 environmental variables describing climate, soil, topography, and vegetation structure, d: temperature dissimilarity based on 11 temperature variables only. All distances are rescaled to a range of [0, 1]. Dashed lines are regression lines.