Niche breadth
Niche breadth was calculated for each clade in the multivariate space
built from the PCA of all bioclimatic variables of current climatic
conditions. For this, the area of the minimum convex polygon from
occurrence points for each genetic clade within the first two dimensions
of the multivariate climatic space (67.05% of variance) was calculated
with the “adehabitatHR” (Calenge, 2023) and “sp” (Pevesma & Bivand,
2005) packages in R. Significant difference of niche breadth was tested
among clade location within taxa (north, south, or unstructured),
taxonomic group (mammal, plant, or reptile) and between elevation
(highland or lowland), using a generalized linear mixed model (GLMM) in
R with the “lme4” package (Bates et al., 2015) with a “gamma”
distribution and an “inverse” link function, and including each taxon
as a random variable.