Testing for shared biogeographic history in the lower Central American freshwater fish assemblage using comparative phylogeography: concerted, independent, or multiple evolutionary responses?

摘要: A central goal of comparative phylogeography is determining whether codistributed species experienced (1) concerted evolutionary responses to past geological and climatic events, indicated by congruent spatial temporal patterns (“concerted-response hypothesis”); (2) independent responses, incongruence (“independent-response or (3) multiple (“multiple-response hypothesis”), congruence but (“pseudocongruence”) (“pseudoincongruence”). We tested these competing hypotheses using DNA sequence data from three livebearing fish in the Nicaraguan depression Central America (Alfaro cultratus, Poecilia gillii, Xenophallus umbratilis) that we predicted might display due co-occurrence identical freshwater drainages. Spatial analyses recovered different subdivisions genetic structure for each species, despite shared finer-scale breaks northwestern Costa Rica (also supported phylogenetic results). Isolation-with-migration models estimated incongruent timelines among-region divergences, with A. cultratus populations diverging over Miocene–mid-Pleistocene while P. gillii diverged mid-late Pleistocene. Approximate Bayesian computation also lent substantial support discrete divergences a model simultaneous divergence across (e.g., Bayes factor [B10] = 4.303 Ψ [no. divergences] > 1 vs. Ψ = 1). Thus, phylogeographic pseudoincongruence consistent multiple-response hypothesis. Model comparisons historical demography, example, intraspecific late Pleistocene population growth was unique P. gillii, evidence expansions other taxa. Empirical tests indicate events have shaped within complex landscapes in/around depression. Recent community assembly through routes (i.e., distributions colonization routes), intrinsic ecological differences among has likely contributed phylogeographical displayed Neotropical fishes.