Ecological niche models
The ecological niche of each clade was modeled by estimating the niche
ellipsoid with the “ntbox” package (Osorio-Olvera et al., 2020a) in R
4.1.2 (R Core Team, 2021). Niche ellipsoids are a useful approximation
to the fundamental niche of a species and hence, allow for a functional
interpretation of the suitability values across clades (Osorio-Olvera et
al., 2019; Osorio-Olvera et al., 2020b). The niche ellipsoid represented
the 95% confidence ellipsoid used by the clade in the multivariate
space built with bioclimatic data (Osorio-Olvera et al., 2020a). We used
the occurrence points from each genetic group, retaining 30% of the
data as a testing set. We determined the best model to describe the
distribution of the genetic clades considering a subset of 3 or 4
variables from the bioclimatic variables after randomly removing one of
each pair with a correlation higher than 0.95. The best model was
selected based on the area under the receiver operating characteristic
curve (AUC).