Biogeographic history and cryptic diversity of saxicolous Tropiduridae lizards endemic to the semiarid Caatinga

BMC Evolutionary Biology

Research Article

Rafael N Leite¹  Miguel T Rodrigues²  Silvia R Geurgas²  Fernanda P Werneck³ 

[1]Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Av. André Araújo 2936, 69060-000, Manaus, AM, Brazil

[2]Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, SP, Brazil

[3]Programa de Coleções Científicas Biológicas, Instituto Nacional de Pesquisas da Amazônia, Av. André Araújo 2936, 69060-000, Manaus, AM, Brazil

[4]Departamento de Zoologia, Universidade de Brasília, 70910-900, Brasília, DF, Brazil

关键词: Neotropics;    Northeastern Brazil;    Speciation;    Species delimitation;    Bayesian phylogeography;    Tropidurus semitaeniatus;    Squamata;   

DOI  :  10.1186/s12862-015-0368-3

 received in 2014-12-05, accepted in 2015-04-29,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundPhylogeographic research has advanced in South America, with increasing efforts on taxa from the dry diagonal biomes. However, the diversification of endemic fauna from the semiarid Caatinga biome in northeastern Brazil is still poorly known. Here we targeted saxicolous lizards of the Tropidurus semitaeniatus species group to better understand the evolutionary history of these endemic taxa and the Caatinga. We estimated a time-calibrated phylogeny for the species group based on two mitochondrial and two nuclear genes and jointly estimated the species limits and species tree within the group. We also devoted a denser phylogeographic sampling of the T. semitaeniatus complex to explore migration patterns, and the spatiotemporal diffusion history to verify a possible role of the São Francisco River as a promoter of differentiation in this saxicolous group of lizards.ResultsPhylogenetic analysis detected high cryptic genetic diversity, occurrence of unique microendemic lineages associated with older highlands, and a speciation history that took place during the Pliocene-Pleistocene transition. Species delimitation detected five evolutionary entities within the T. semitaeniatus species group, albeit with low support. Thus, additional data are needed for a more accurate definition of species limits and interspecific relationships within this group. Spatiotemporal analyses reconstructed the geographic origin of the T. semitaeniatus species complex to be located north of the present-day course of the São Francisco River, followed by dispersal that expanded its distribution towards the northwest and south. Gene flow estimates showed higher migration rates into the lineages located north of the São Francisco River.ConclusionsThe phylogenetic and population structures are intrinsically associated with stable rock surfaces and landscape rearrangements, such as the establishment of drainage basins located to the northern and southern distribution ranges. The T. semitaeniatus complex preserved high genetic diversity during range expansion, possibly as a result of frequent long-distance dispersal events. Our results indicate that both the current course of the São Francisco River and its paleo-courses had an important role in promoting diversification of the Caatinga endemic T. semitaeniatus species group.

【 授权许可】

CC BY   
© Werneck et al.; licensee BioMed Central. 2015