Niche patterns on the Baja Peninsula
Genetically divergent groups on the peninsula presented ecological niche divergence for all between-clade comparisons (Supporting Information). This agrees with previous studies including some of the same taxa (Cab-Sulub & Álvarez-Castañeda, 2021), and expands the niche divergence pattern further than just North-South of the Vizcaino region, but also between clades within a same region of the peninsula. This suggests that some species could have adapted to the high diversity of available environmental conditions, and could explain the high variation in the location of genetic breaks previously documented (Dolby et al., 2015; Araya-Donoso et al., 2022).
Niche breadth differed between clades located in the north and south of the peninsula (Figure 2), whereas elevation and taxonomic group showed no effect on niche breadth. The niche breadth was wider in northern clades than in southern clades, which could shape how populations responded to glacial oscillations (Carscadden et al., 2020). This is associated with a generally wider heterogeneity of available climatic conditions in the north than in the south. However, after standardizing by geographic area, the niche breadth in the north and south are similar (Supporting Information). It is important to note however that the niche utilization at the scale of the organism can differ greatly from predictions on a macroenvironmental scale (Ficetola et al., 2018). Therefore, there may be less niche divergence than predicted by these models if organisms are experiencing microclimates that are less apparent at a macro scale.