Bayesian analyses detect a history of both vicariance and geodispersal in Neotropical freshwater fishes

Author(s)

Machado, Carolina Barros ^[1] ; Galetti, Jr., Pedro Manoel ^[1] ; Carnaval, Ana Carolina ^{[2, 3]}

Affiliation

^[1] Univ Fed Sao Carlos, Dept Genet & Evolucao, Sao Carlos, SP - Brazil

^[2] CUNY, Grad Ctr, New York, NY - USA

^[3] CUNY, City Coll New York, Dept Biol, New York, NY 10021 - USA

• Document type: Journal article
• Source: Journal of Biogeography; v. 45, n. 6, p. 1313-1325, JUN 2018.
• Web of Science Citations: 1

Abstract

Aim: Among the main biogeographical hypotheses explaining the remarkable diversity of fishes in the Neotropics is the ``palaeogeographical hypothesis{''}, focusing on vicariance, and the ``hydrogeological hypothesis{''}, focusing on geodispersal. Yet while reflecting different processes, they may result in similar biogeographical patterns. We employed a model-based Bayesian approach to test these alternative hypotheses and determine which shaped the phylogeographical patterns observed in a group of Neotropical fishes. Location: South America. Taxon: Salminus. Methods: We used mitochondrial and nuclear markers to infer phylogenetic relationships and estimate divergence times among Salminus species, associating the results with known geological events. We then employed approximate Bayesian computation (ABC) to explore changes in population size over time, asking whether vicariance or geodispersal events best explain the phylogeographical signature observed in the data. Because geodispersal captures a few individuals from a parental population, which can then expand and lead to a new lineage, we expect to find genetic signatures of a founder event following population expansion under this scenario, but not under vicariance. Results: The analyses suggest that the diversification process in Salminus beganin Upper Miocene, and ABC indicates that it involved both vicariance andgeodispersal events: while a vicariance event better explains the phylogeographical structure within S. brasiliensis and the genetic patterns of differentiation between S. sp. Amazon and S. sp. Araguaia, geodispersal appearsto have been the most important event structuring lineages of Salminus hilarii. Main Conclusions: Both vicariance and geodispersal signatures were detected in our biological model, inferring a complex yet realistic demographic history of Salminus lineages. The correspondence between the ABC results and traditional phylogeographical interpretations provide further confidence in the models drawnand tested. This study reinforces the value of applying an ABC frameworkin phylogeographical studies, particularly for those interested in testing alternative and biologically plausible processes underlying similar biogeographical patterns. (AU)

• FAPESP's process: 10/52315-7 - Top predators of food chain
• Grantee: Pedro Manoel Galetti Junior
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 13/50297-0 - Dimensions US-BIOTA São Paulo: a multidisciplinary framework for biodiversity prediction in the Brazilian Atlantic forest hotspot
• Grantee: Cristina Yumi Miyaki
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants