Different patterns of niche marginality during LGM for highland and lowland species
We incorporated two measures of niche marginality in our analyses to assess habitat quality within our models, which allowed us to infer changes in population fitness and putative selection pressure from LGM to present. We detected higher centroid niche marginality during LGM for most clades, particularly southern highland clades (Figure 3a). Moreover, within suitable areas some clades presented a higher proportion of more marginal conditions during LGM (Figure 4). Both approaches showed consistent results, however the full distribution of marginal areas provided a more detailed description of how habitat quality changed through time. Despite a general reduction in the amount of habitat for all clades and species during LGM, changes in habitat quality between LGM and present day differed among desert-adapted lowland taxa and cold-adapted highland taxa. For lowland desert-adapted species, available environmental conditions were in general more challenging during LGM (Figure 3, Figure 4), and in the desert regions from the southern peninsula habitat quality improved more LGM to present relative to the north (Figure 3, Figure 4). In contrast, for most highland species habitat quality seems to have declined since LGM, but particularly in the Northern part of the Peninsula (Figure 3, Figure 4). Highland species generally present adaptations to cold environments, such as sustained activity during suboptimal temperatures in the lizardElgaria multicarinata (Kingsbury, 1994) or the structure of needles in Pinus species (Jankowski et al. 2019). Highland species being favored during LGM conditions is consistent with studies from other regions such as the Afromontane forests range expansions in the Horn of Africa (Casas-Gallego et al., 2023), or Polyepsiswoodlands on the Andes Mountains (Zutta & Rundel, 2017).