Genomic model-based comparative phylogeography of Atlantic Forest lizards: reconstructing historical demography and divergence history in a hotspot

Abstract

How did the late Pleistocene climatic oscillations affect lineage divergence and population sizes of species with overlapping distributions in the Brazilian Atlantic Forests? And how congruent were demographic responses across those species? In order to answer those questions we propose a genomic, model-based, and comparative phylogeography study in the Brazilian Atlantic Forests (AF) to investigate divergence history and historical demography of three lizard species, using a rigorous model-based framework, up-to-date statistical methods, and cutting-edge sequencing technology. Accumulating evidence suggest that climatically stability in the AF over the Pleistocene allowed long-term persistence and geographic restriction of phylogeographic endemisms. However, recent evidence of mito-nuclear discordances, of recent population expansion, and of hybridization between species, suggest a much more dynamic history in the region. In this context, we are going to use approximate Bayesian computation (ABC) methods and an existing genetic dataset to test if divergence of intraspecific lineages occurred before or during the late Pleistocene and if gene flow occurred during divergence. As inference strength of ABC methods increases with data availability, we are going to generate a genomic dataset (minimum 10,000 SNPs) for two species, using ddrADSeq technology, and in the future we are going to perform similar ABC analyses, comparing results across datasets. Besides generating novel insight on the AF history, this proposal has the potential to serve as a template for studies on divergence history and historical demography in mega-diverse regions worldwide. (AU)