Linking environmental stability with genetic diversity and population structure in two Atlantic Forest palm trees

Spatial patterns of biodiversity in the Atlantic Forest of Brazil are well characterized. However, there is no consensus on the biological processes underlying these patterns, and multiple competing hypotheses have been proposed, several of which center on climatic stability. Here, we ask if Late Quaternary climatic stability predicts contemporary population structure and genomic-level diversity in two palm species: Syagrus botryophora and S. pseudococos (Arecaceae)
We first use species occurrence data to model the distribution of suitable environments in 62 time-slice climate projections over the last 120 thousand years, and summarize stability over that period. We then use >25,000 RADseq-generated SNPs to i) describe the spatial patterns of genomic variation in both species, ii) test how well genomic variation is explained by isolation by distance and by the environmental resistance imposed by historical instability (isolation by resistance) and iii) test for a correlation between ...