Evidence of introgression in endemic frogs from the campo rupestre contradicts the reduced hybridization hypothesis

Author(s)

Magalhaes, Rafael F. ^{[1, 2, 3]} ; Lemes, Priscila ^[4] ; Santos, Marcus Thadeu T. ^[5] ; Mol, Rafael M. ^[2] ; Ramos, Elisa K. S. ^[6] ; Oswald, Caroline B. ^[2] ; Pezzuti, Tiago L. ^[2] ; Santos, Fabricio R. ^{[2, 3]} ; Brandao, Reuber A. ^{[7, 8]} ; Garcia, Paulo C. A. ^[2]

Affiliation

^[1] Univ Fed Sao Joao del Rei, Dept Ciencias Nat, Sao Joao Del Rei, MG - Brazil

^[2] Univ Fed Minas Gerais, Dept Zool, Programa Posgrad Zool, Belo Horizonte, MG - Brazil

^[3] Univ Fed Minas Gerais, Dept Genet Ecol & Evolucao, Lab Biodiversidade & Evolucao Mol, Belo Horizonte, MG - Brazil

^[4] Univ Fed Mato Grosso, Inst Biociencias, Dept Bot & Ecol, Lab Ecol & Conservacao, Cuiaba, Mato Grosso - Brazil

^[5] Univ Estadual Paulista, Inst Biociencias, UNESP, Programa Posgrad Zool, Rio Claro, SP - Brazil

^[6] Univ Estadual Campinas, Dept Genet Evolucao Microbiol & Imunol, Programa Posgrad Genet & Biol Mol, Sao Paulo, SP - Brazil

^[7] Univ Brasilia, Dept Engn Florestal, Lab Fauna, Brasilia, DF - Brazil

^[8] Univ Brasilia, Dept Engn Florestal, Unidades Conservacao, Brasilia, DF - Brazil

• Document type: Journal article
• Source: Biological Journal of the Linnean Society; v. 133, n. 2, p. 561-576, JUN 2021.
• Web of Science Citations: 2

Abstract

The campo rupestre ecosystem is considered an old, climatically buffered, infertile landscape. As a consequence, long-term isolation is thought to have played an important role in the diversification of its biota. Here, we tested for hybridization between two endemic leaf frogs from the campo rupestre. We used sequence markers and coalescent models to verify haplotype sharing between the species, to test the existence and direction of gene flow, and to reconstruct the spatiotemporal dynamics of gene flow. Additionally, ecological niche modelling (ENM) was used to assess for potential co-occurrence by overlapping the climatic niche of these species since the middle Pleistocene. We found haplotype sharing and/or lack of differentiation in four nuclear fragments, one of them associated with introgression. The coalescent models support introgressive hybridization unidirectionally from Pithecopus megacephalus to P. ayeaye, occurring similar to 300 kya. ENM corroborates this scenario, revealing areas of potential environmental niche overlap for the species at about 787 kya. These results contradict the expectation of reduced hybridization, while ENM suggests climatic fluctuation rather than stability for the two species. The reduced hybridization hypothesis needs to be further investigated because our results suggest that it may have unrealistic premises at least for animals. (AU)

• FAPESP's process: 14/22344-6 - The effects of climate and land-use changes and their consequences in amphibian conservation in Brazil
• Grantee: Priscila Lemes de Azevedo Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral