Ecology and Evolution 2012; 2(5): 1024–1035
Phylogeography of Tibouchina papyrus (Pohl) Toledo (Melastomataceae), an endangered tree species from rocky savannas, suggests bidirectional expansion due to climate cooling in the Pleistocene
Article first published online: 12 APR 2012
© 2011 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.
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Ecology and Evolution
Volume 2, Issue 5, pages 1024–1035, May 2012
How to Cite
Collevatti, R. G., de Castro, T. G., de Souza Lima, J. and de Campos Telles, M. P. (2012), Phylogeography of Tibouchina papyrus (Pohl) Toledo (Melastomataceae), an endangered tree species from rocky savannas, suggests bidirectional expansion due to climate cooling in the Pleistocene. Ecology and Evolution, 2: 1024–1035. doi: 10.1002/ece3.236
- Issue published online: 10 MAY 2012
- Article first published online: 12 APR 2012
- Received: 15 November 2011; Revised: 5 February 2012; Accepted: 8 February 2012
- Cerrado rupestre;
- climatic relict;
- coalescent analysis;
- disjunct geographical distribution;
Many endemic species present disjunct geographical distribution; therefore, they are suitable models to test hypotheses about the ecological and evolutionary mechanisms involved in the origin of disjunct distributions in these habitats. We studied the genetic structure and phylogeography of Tibouchina papyrus (Melastomataceae), endemic to rocky savannas in Central Brazil, to test hypothesis of vicariance and dispersal in the origin of the disjunct geographical distribution. We sampled 474 individuals from the three localities where the species is reported: Serra dos Pirineus, Serra Dourada, and Serra de Natividade. Analyses were based on the polymorphisms at cpDNA and on nuclear microsatellite loci. To test for vicariance and dispersal we constructed a median-joining network and performed an analysis of molecular variance (AMOVA). We also tested population bottleneck and estimated demographic parameters and time to most recent common ancestor (TMRCA) using coalescent analyses. A remarkable differentiation among populations was found. No significant effect of population expansion was detected and coalescent analyses showed a negligible gene flow among populations and an ancient coalescence time for chloroplast genome. Our results support that the disjunct distribution of T. papyrus may represent a climatic relict. With an estimated TMRCA dated from ∼836.491 ± 107.515 kyr BP (before present), we hypothesized that the disjunct distribution may be the outcome of bidirectional expansion of the geographical distribution favored by the drier and colder conditions that prevailed in much of Brazil during the Pre-Illinoian glaciation, followed by the retraction as the climate became warmer and moister.