Historical biogeography of New World Killifishes (Cyprinodontiformes: Funduloidea) recapitulates geographical history in the Gulf of México watershed

Abstract

ABSTRACTWe reconstructed the phylogenetic relationships of superfamily Funduloidea with a synthesis of its biogeographic history. We used DNA sequences from five genes for 135 species, with four fossil calibrations, to generate a time-calibrated phylogeny. We estimated diversification rates, ancestral areas (Nearctic or Neotropical), and ancestral habitat (coastal or upland), for each node. Our results suggest that Funduloidea originated in the Late Cretaceous and diversified from Late Paleocene to present at a uniform rate, except Cyprinodontidae expressed an accelerated rate of speciation ~11.02 Ma. Neither viviparity, marine-to-freshwater transition, consistently accelerated speciation. Funduloidea has a coastal origin, but invaded inland many times. Funduloidea phylogeny indicates, sea-level falls isolate coastal populations, but increase island accessibility and climatic cooling facilitates invasions of temperate species into the tropics. For continental lineages, ancient river drainages accord with lineage distributions, including enigmatic disjunctions in Goodeidae andFundulus. Niche shifts occurred from estuaries to open coasts and from forests to grasslands. Antiquity, adaptability, and dynamic geography can explain Funduloidea diversity. Combined environmental and phylogenetic data unveil the history of the Gulf of México watershed. Phylogeny suggests there was diversification by barrier displacement and coastal speciation pump. Overall, speciation time, transitions to freshwater, dispersal, vicariance, adaptive radiation, and viviparity contributed to total diversification.