Agradecimentos: We want to thank the following for their assistance: ICMBio for the collection permits (# 32601-5 and 32601-3), Maria Tereza Chiarioni Thomé for her help with ABC, Alain Chautems and Gabriel Emiliano Ferreira for fieldwork help, and Célia Bresil for technical support. We appreciate...

Agradecimentos: We want to thank the following for their assistance: ICMBio for the collection permits (# 32601-5 and 32601-3), Maria Tereza Chiarioni Thomé for her help with ABC, Alain Chautems and Gabriel Emiliano Ferreira for fieldwork help, and Célia Bresil for technical support. We appreciate the suggestions of the three anonymous reviewers. Lastly, we thank the following entities for financial support: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the master’s fellowship to CFF and grants to VNS and ELB; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for their master’s fellowship to CFF; and São Paulo Research Foundation (FAPESP), with grants # 2012/02526-7 to VNS and 2011/20269-9 to AOA

The area occupied by tropical forests in South America has continually experienced shrinkage since the Miocene, with the formation of the Dry Diagonal, which is composed of seasonally dry tropical forests and savannas (Caatinga, Cerrado, and Chaco). Here, we contribute to the understanding of the...

The area occupied by tropical forests in South America has continually experienced shrinkage since the Miocene, with the formation of the Dry Diagonal, which is composed of seasonally dry tropical forests and savannas (Caatinga, Cerrado, and Chaco). Here, we contribute to the understanding of the establishment of the Dry Diagonal by testing the hypotheses of “ancestral fragmentation” and of “colonization” to explain the current distribution of species in rocky humid formations of Cerrado, a Neotropical savanna in Brazil. Populations of Mandirola hirsuta (Gesneriaceae) were sampled in 25 localities; these cover the species’ entire geographical distribution, and the plastid intergenic regions psbA-trnH and trnQ-5′-rps16 were sequenced. The findings show that intrapopulation genetic variability was low, whereas interpopulation variability was high. We detected seven genetic groups that were geographically well delimited, and no signs of recent population expansion were observed. Divergence between the seven main lineages took place between the late Miocene and the Pliocene periods. In Approximate Bayesian Computation, the fragmentation scenario had a significantly higher probability than the colonization scenario. Results support the hypothesis of a former broader distribution for the humid vegetation, which was fragmented with the expansion of savannas; results also indicate population differentiation promoted by a rapid expansion of the Dry Diagonal

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2012/02526-7; 2011/20269-9

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

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