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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Phylogeography of the dry vegetation endemic species Nephila sexpunctata (Araneae: Araneidae) suggests recent expansion of the Neotropical Dry Diagonal

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de Macedo Bartoleti, Luiz Filipe ; Peres, Elen Arroyo ; Sobral-Souza, Thadeu ; Mascarenhas Fontes, Fernanda von Hertwig ; da Silva, Marcio Jose ; Solferini, Vera Nisaka
Total Authors: 6
Document type: Journal article
Source: Journal of Biogeography; v. 44, n. 9, p. 2007-2020, SEP 2017.
Web of Science Citations: 7

Aim The Neotropical Dry Diagonal (DD) is a corridor of distinct dry environments in central South America. The main hypotheses suggest that these environments may have expanded during the glacial cycles together with a retraction of rainforests, and then shrank when the climate became wetter and warmer. However, few studies have explicitly tested the hypotheses on DD evolution. We conducted a phylogeographical study on Nephila sexpunctata, a spider endemic to Neotropical dry habitats, to enrich the understanding of DD evolutionary history. Location South-western portion of the DD (Cerrado and Chaco). Methods We sequenced two mitochondrial regions and one nuclear DNA region of 65 individuals from 10 locations across the species' range. We conducted analyses of genetic structure, variability, demography and inferred divergence times. We used an ecological niche modelling framework to generate hypotheses on the species' distribution along the last glacial cycle and a model-based approach to test the demographical scenarios that might explain the genetic patterns. Results Both markers presented low genetic diversity. Mitochondrial markers had high genetic structure, with specific geographical lineages within each biome, while the nuclear marker presented low genetic structure. Phylogeo-graphical and demographical events encompass the last glacial cycle, with a strong post-Last Glacial Maximum (LGM) population and spatial expansion. Model testing corroborated the recent demographical expansion of N. sexpunctata. Main Conclusions Our data suggest that Quaternary climate cycles, when moist forests periodically expanded towards the dry vegetation, influenced the diversification of DD organisms by promoting demographical events. These events might explain the genetic structure observed in N. sexpunctata; differently from what was expected by the Pleistocene refugia model, some DD species may have experienced post-LGM expansion. Climate and geological events have both affected DD-endemic organisms' diversification. (AU)

FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
Grantee:Munir Salomao Skaf
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 12/02526-7 - Phylogeography and populational genetic structure of spiders species (Arachnida, Araneae)
Grantee:Vera Nisaka Solferini
Support type: Regular Research Grants