Niche differentiation between clades
To assess climatic niche differentiation between clades, we calculated
the niche overlap based on niche ellipsoids with the “ellipsenm”
package (Cobos et al., 2020) in R. The niche overlap corresponds to a
value between 0 and 1, where 1 represents complete overlap and 0
represents no overlap. Niche overlap was calculated with the first three
principal components obtained from a principal component analysis (PCA)
of all scaled bioclimatic variables (See Supporting Information for
details). We compared all clade pairs within taxa, and significance was
obtained from 1,000 bootstrap replicates.