Neither barriers nor refugia explain genetic structure in a major biogeographic break: phylogeography of praying mantises in the Brazilian Atlantic Forest

Abstract

The Atlantic Forest is one of the world’s top biodiversity hotspots, but the diversification processes of its biota are still poorly known, with competing models attributing dominant roles to either Quaternary climatic changes or geographic barriers. Many studies identify the Doce river as a major phylogeographic break, but the reasons for this phenomenon are highly debated. Here we test the predictions of the refugial and barrier models for a common species of praying mantis, Miobantia fuscata, focusing in the areas immediately south and north of the Doce river. Our analyses show high intraspecific genetic diversity, deep coalescence times and no evidence for recent population expansion. Phylogeographic structure is inconsistent with a refugial hypothesis. Significant gene flow between northern and southern populations also conflicts with a strong role for geographic barriers. This study highlights the need for considering invertebrate taxa to infer recent landscape changes, and points towards a more complex picture of genetic diversification in the Atlantic Forest.

Keywords:

• Doce river
• central corridor
• Miobantia
• Mantodea
• Thespidae

Acknowledgements

George Barrowclough, Rob DeSalle and Susan Perkins (AMNH) provided encouragement and advice in early stages of this work. Marcelo T. Tavares kindly loaned all examined specimens from the UFES collection. Ricardo Monteiro (UFRJ) and Mirco Solé (UESC) provided specimens of Miobantia from other species used as comparative material. Alexandre P. Aguiar and Valéria Fagundes (UFES) were mentors to M. V. S. during a preliminary stage of this work. Valéria also kindly hosted M. V. S. in her lab during the generation of sequence data.

Disclosure statement

The authors have identified no conflict of interest to declare.

Additional information

Funding

B. F. S. was supported by a graduate student fellowship from the Richard Gilder Graduate School and the Peter Buck Postdoctoral Fellowship at the Smithsonian Institution. A. C. L. has a postdoctoral scholarship from Fundação de Amparo à Pesquisa e Inovação do Estado do Espírito Santo-FAPES/CAPES [Grant no. 68854315/14]. M. V. S. has a graduate fellowship from the Comissão de Aperfeiçoamento de Pessoal Superior. The Sackler Institute of Comparative Genomics funded some of the DNA sequencing.