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Advisor(s)
Abstract(s)
Recent studies have focused on the relationship between the marine fauna of the eastern Atlantic and the Mediterranean Sea, but
within the Atlantic, little is known about genetic relationships between populations of the Macaronesian islands. In this study, we tested
whether the paleo-climatology and paleo-oceanography of the region could predict the genetic relationships among three eastern Atlantic
populations (Azores, Madeira, and Canaries) of a damselWsh, Chromis limbata, and compared our results with its Mediterranean and
adjacent Atlantic sister species, Chromis chromis. We combined phylogeographic and coalescent approaches using the fast evolving mitochondrial
control region gene. No population structure was found for the three archipelagos. The coalescence time estimated for C. limbata
(0.857–1.17Mya) was much greater than that estimated for C. chromis. We propose that this diVerence reXects diVerences in
glaciating extents in the Northeastern Atlantic and the Mediterranean. Diversity indexes (Hd and genetic distances) together with historical
demographic parameters of C. limbata ( and g) revealed a more stable population history when compared to C. chromis. Our results
suggest that the Macaronesian populations of C. limbata have probably been less aVected by the last glaciation than the Mediterranean
populations of C. chromis. Migration across the three archipelagos was estimated and a prevailing northwest trend was detected. This
result supports the idea of a colonization of the Azores by warm water Wsh from Madeira or the westernmost Canary islands which acted
as major glacial refugia for the tropical and subtropical marine fauna during the glaciations.
Description
Keywords
Chromis limbata Northeastern Atlantic islands Phylogeography Glaciations D-loop
Citation
Molecular Phylogenetics and Evolution, 40, 139-147
Publisher
Elsevier