Evolving in the highlands: the case of the Neotropical Lerma live-bearing Poeciliopsis infans (Woolman, 1894) (Cyprinodontiformes: Poeciliidae) in Central Mexico

Abstract Background Volcanic and tectonic activities in conjunction with Quaternary climate are the main events that shaped the geographical distribution of genetic variation of many lineages. Poeciliopsis infans is the only poeciliid species that was able to colonize the temperate highlands of central Mexico. We inferred the phylogenetic relationships, biogeographic history, and historical demography in the widespread Neotropical species P. infans and correlated this with geological events and the Quaternary glacial-interglacial climate in the highlands of central Mexico, using the mitochondrial genes Cytochrome b and Cytochrome oxidase I and two nuclear loci, Rhodopsin and ribosomal protein S7. Results Populations of P. infans were recovered in two well-differentiated clades. The maximum genetic distances between the two clades were 3.3% for cytb, and 1.9% for coxI. The divergence of the two clades occurred ca. 2.83 Myr. Ancestral area reconstruction revealed a complex biogeographical history for P. infans. The Bayesian Skyline Plot showed a demographic decline, although more visible for clade A, and more recently showed a population expansion in the last 0.025 Myr. Finally, the habitat suitability modelling showed that during the LIG, clade B had more areas with high probabilities of presence in comparison to clade A, whereas for the LGM, clade A showed more areas with high probabilities of presence in comparisons to clade B. Conclusions Poeciliopsis infans has had a complex evolutionary and biogeographic history, which, as in other co-distributed freshwater fishes, seems to be linked to the volcanic and tectonic activities during the Pliocene or early Pleistocene. Populations of P. infans distributed in lowlands showed a higher level of genetic diversity than populations distributed in highlands, which could be linked to more stable and higher temperatures in lowland areas. The fluctuations in population size through time are in agreement with the continuous fluctuations of the climate of central Mexico.This work was conducted as part of the doctoral studies of R. G. Beltrán-López, and she was supported with a scholarship from the Consejo Nacional de Ciencia y Tecnología (CONACYT: scolarship number 329883). We thank Isaí Betancourt for his help with sampling, and to Berenice García Andrade and Silvia Perea for their help in laboratory and for their comments to improve this work. We thank three anonymous reviewers for their comments that improved this manuscript.Funding for this study was provided by the Ministerio de Economía y Competitividad y FEDER, Spain (CGL2016–75262-P) to ID and PRODEM, CIC-UMSNH, Chester Zoo garden and CONACYT sabbatical grant to ODD, as well as funds from the U.S. National Science Foundation (DEB 1354930) to KRP. These funding body do not had a specific role in the design of the study and collection, analyses, and interpretation of data in writing the manuscript