Multilocus phylogeny and historical biogeography of Hypostomus shed light on the processes of fish diversification in La Plata Basin

Distribution history of the widespread Neotropical genus Hypostomus was studied to shed light on the processes that shaped species diversity. We inferred a calibrated phylogeny, ancestral habitat preference, ancestral areas distribution, and the history of dispersal and vicariance events of this genus. The phylogenetic and distribution analyses indicate that Hypostomus species inhabiting La Plata Basin do not form a monophyletic clade, suggesting that several unrelated ancestral species colonized this basin in the Miocene. Dispersal to other rivers of La Plata Basin started about 8 Mya, followed by habitat shifts and an increased rate of cladogenesis. Amazonian Hypostomus species colonized La Plata Basin several times in the Middle Miocene, probably via the Upper Paraná and the Paraguay rivers that acted as dispersal corridors. During the Miocene, La Plata Basin experienced marine incursions, and geomorphological and climatic changes that reconfigured its drainage pattern, driving dispersal and diversification of Hypostomus. The Miocene marine incursion was a strong barrier and its retraction triggered Hypostomus dispersal, increased speciation rate and ecological diversification. The timing of hydrogeological changes in La Plata Basin coincides well with Hypostomus cladogenetic events, indicating that the history of this basin has acted on the diversification of its biota.Fil: Cardoso, Yamila Paula. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Sistemática y Biología Evolutiva; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Jardim de Queiroz, Luiz. Universidad de Ginebra; SuizaFil: Bahechar, Ilham A.. Universidad de Ginebra; SuizaFil: Posadas, Paula Elena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Sistemática y Biología Evolutiva; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Montoya Burgos, Juan Ignacio. Universidad de Ginebra; Suiz

Multilocus phylogeny and historical biogeography of <i>Hypostomus</i> shed light on the processes of fish diversification in La Plata Basin

Distribution history of the widespread Neotropical genus Hypostomus was studied to shed light on the processes that shaped species diversity. We inferred a calibrated phylogeny, ancestral habitat preference, ancestral areas distribution, and the history of dispersal and vicariance events of this genus. The phylogenetic and distribution analyses indicate that Hypostomus species inhabiting La Plata Basin do not form a monophyletic clade, suggesting that several unrelated ancestral species colonized this basin in the Miocene. Dispersal to other rivers of La Plata Basin started about 8 Mya, followed by habitat shifts and an increased rate of cladogenesis. Amazonian Hypostomus species colonized La Plata Basin several times in the Middle Miocene, probably via the Upper Parana and the Paraguay rivers that acted as dispersal corridors. During the Miocene, La Plata Basin experienced marine incursions, and geomorphological and climatic changes that reconfigured its drainage pattern, driving dispersal and diversification of Hypostomus . The Miocene marine incursion was a strong barrier and its retraction triggered Hypostomus dispersal, increased speciation rate and ecological diversification. The timing of hydrogeological changes in La Plata Basin coincides well with Hypostomus cladogenetic events, indicating that the history of this basin has acted on the diversification of its biota.Facultad de Ciencias Naturales y MuseoLaboratorio de Sistemática y Biología Evolutiv

The contribution of neutral evolution and adaptive processes in driving phenotypic divergence in a model mammalian species, the Andean fox Lycalopex culpaeus

Aim: Understanding the mechanisms that drive phenotypic divergence along climatic gradients is a long-standing goal of biogeography. To fulfil this objective, we tested if neutral and/or adaptive effects drive phenotypic diversification. We quantified the effects of neutral evolution and natural selection on morphological variability of a well-suited mammalian species, the fox, Lycalopex culpaeus. Location: South America. Methods: We analysed variations in skull shape, jaw shape and skull size in L. culpaeus. The processes underlying our models were: local adaptation, and short- or long-term neutral evolution. We inferred genetic population structure using mitochondrial and nuclear markers, we quantified morphological differences among populations by performing geometric morphometric analyses, and we inferred an ecological niche model for calculating environmental resistance between populations. Results: We identified six genetically differentiated populations of the Andean fox, which correspond well to the described subspecies. We showed that skull shape variation is explained by population structure. Skull size showed a clear Bergmannian pattern with larger animals in higher latitudes (in absolute values). Skull size divergence is driven by the combined effects of environmental factors and population structure. Intriguingly, none of the models explains the variation observed in jaw shape. Main Conclusion: Population phenotypic variation in the Andean fox L. culpaeus is driven by deterministic and neutral processes. The methodological framework presented here opens up new opportunities to study phenotypic evolution; it allowed us to demonstrate that the processes explaining trait variation can differ among traits and to show empirically for the first time that a trait can diverge among populations due to simultaneous adaptation and neutral evolution.Fil: Martinez, Pablo A.. Universidade Federal do Rio Grande do Norte; Brasil. Universidade Federal de Sergipe; BrasilFil: Pia, Monica Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Bahechar, Ilham A.. Universidad de Ginebra; SuizaFil: Molina, Wagner F.. Universidade Federal do Rio Grande do Norte; BrasilFil: Bidau, Claudio Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Montoya Burgos, Juan Ignacio. Universidad de Ginebra; Suiz

Western Amazon was a center of Neotropical fish dispersal, as evidenced by the continental-wide time-stratified biogeographic analysis of the hyper-diverse Hypostomus catfish

The Amazon is probably the most diverse realm on Earth, and is considered to be the primary source of diversity and a center of dispersal for Neotropical terrestrial organisms. Yet, the assumption that the Amazon basin is a primordial place of fish species origination and dispersal into other drainages still need to be tested. We addressed this issue by inferring a time-stratified biogeographic history and reconstructing the ancestral habitat preference of Hypostomus, a continentally widespread and species-rich Neotropical genus. We found that Hypostomus emerged in the Western Amazon ([~]14.7 Ma), when the Western Amazon River was flowing northwards and disconnected from the Eastern Amazon. We show that dispersal events in the first half of Hypostomus evolution occurred from the Western Amazon into adjacent basins, initiating its Neotropical radiation. The ancestral preferred habitat consisted in small rivers with running waters, a predominant habitat in river headwaters. Because of strong niche conservatism in the early evolution of Hypostomus, we suggest that most of the out-of-Western-Amazon dispersal occurred via headwater captures. The radiation of Hypostomus was further promoted by major reconfigurations of river basins, which opened dispersal opportunities into new drainages. Diversification in habitat preference coincided with colonization of basins already occupied by congenerics, indicative of niche shifts triggered by inter-specific competition and species coexistence. By analyzing the evolutionary history of Hypostomus, we show that Western Amazon was the main center of fish dispersal in the Neotropical Region from Middle Miocene to the present, supporting the cradle hypothesis of fish origination and dispersal.Laboratorio de Sistemática y Biología Evolutiv