Extended Data Fig. 4: Schematic of all demographic models tested with fastsimcoal2.

Two different tree topologies and 12 models per topology were tested. We considered the topology that retrieves both H. elevatus and H. pardalinus as monophyletic; that is, the species tree, (topology 1) and the most frequent topology across the genome (Extended Data Fig. 2), after excluding gene flow between H. elevatus and Amazonian H. pardalinus and in which H. p. sergestus is the first population to split (topology 2). The different demographic models are split into five main categories (depicted in different boxes): SI, strict isolation; AM, ancestral migration; SC, secondary contact; AM-SC, ancestral migration followed by secondary contact; IM, isolation with migration. Arrows between demes indicate gene flow (each direction being estimated as an independent parameter). Effective population sizes were allowed to change at split times. Note that for models under tree topology 1, the split times between H. elevatus populations and between H. pardalinus populations are different parameters and thus can assume different values.