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© 2014. This work is published under http://creativecommons.org/licenses/by/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

The accuracy of phylogenetic inference can be significantly improved by the addition of more taxa and by increasing the spatial coverage of sampling. In previous studies, the brown mussel Perna perna showed a sister–lineage relationship between eastern and western individuals contiguously distributed along the South African coastline. We used mitochondrial (COI) and nuclear (ITS) sequence data to further analyze phylogeographic patterns within P. perna. Significant expansion of the geographical coverage revealed an unexpected pattern. The western South African lineage shared the most recent common ancestor (MRCA) with specimens from Angola, Venezuela, and Namibia, whereas eastern South African specimens and Mozambique grouped together, indicating a non-sister relationship for the two South African lineages. Two plausible biogeographic scenarios to explain their origin were both supported by the hypotheses-testing analysis. One includes an Indo-Pacific origin for P. perna, dispersal into the Mediterranean and Atlantic through the Tethys seaway, followed by recent secondary contact after southward expansion of the western and eastern South African lineages. The other scenario (Out of South Africa) suggests an ancient vicariant divergence of the two lineages followed by their northward expansion. Nevertheless, the “Out of South Africa” hypothesis would require a more ancient divergence between the two lineages. Instead, our estimates indicated that they diverged very recently (310 kyr), providing a better support for an Indo-Pacific origin of the two South African lineages. The arrival of the MRCA of P. perna in Brazil was estimated at 10 [0–40] kyr. Thus, the hypothesis of a recent introduction in Brazil through hull fouling in wooden vessels involved in the transatlantic itineraries of the slave trade did not receive strong support, but given the range for this estimate, it could not be discarded. Wider geographic sampling of marine organisms shows that lineages with contiguous distributions need not share a common ancestry.

Details

Title
Wider sampling reveals a non-sister relationship for geographically contiguous lineages of a marine mussel
Author
Cunha, Regina L 1 ; Nicastro, Katy R 1 ; Costa, Joana 1 ; McQuaid, Christopher D 2 ; Serrão, Ester A 1 ; Zardi, Gerardo I 3 

 Centre of Marine Sciences – CCMAR, Campus de Gambelas, Universidade do Algarve, 8005-139, Faro, Portugal 
 Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa 
 Centre of Marine Sciences – CCMAR, Campus de Gambelas, Universidade do Algarve, 8005-139, Faro, Portugal; Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa 
Pages
2070-2081
Section
Original Research
Publication year
2014
Publication date
Jun 2014
Publisher
John Wiley & Sons, Inc.
e-ISSN
20457758
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2290153321
Copyright
© 2014. This work is published under http://creativecommons.org/licenses/by/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.