influence of glacial epochs and habitat dependence on the diversity and phylogeography of a coastal dolphin species: Lagenorhynchus albirostris

• Published in: Conservation genetics 2010-10, Vol.11 (5), p.1823-1836
• Main Authors: Banguera-Hinestroza, E, Bjørge, A, Reid, R. J, Jepson, P, Hoelzel, A. R
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Aquatic mammals; Biodiversity; Biogeography; Conservation biology; Conservation Biology/Ecology; Deep water; Demographic expansion; Dolphins & porpoises; Ecology; Evolutionary Biology; Genetic diversity; Lagenorhynchus; Life Sciences; Local population; Marine mammals; Mitochondrial DNA; North Atlantic; phylogeography; Plant Genetics and Genomics; Population genetics; Population structure; Research Article; Spatial expansion; White-beaked dolphins
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-010-0075-y

In this paper we use mitochondrial and microsatellite DNA variation to investigate the mechanisms that underlie the evolution of population structure in a highly mobile marine mammal, the white-beaked dolphin. We found moderate genetic diversity (h) at mtDNA, but low nucleotide diversity (π) (0.7320 ± 0.0031 and 0.0056 ± 0.0004, respectively), consistent with expectations for a recent expansion. Analyses based on mismatch distributions further suggested a demographic expansion in the Norwegian-Barents Sea population and a spatial expansion in the British isles-North Sea population, implying distinct demographic histories. F ST values showed clear differentiation among these two populations, but no difference was found between putative populations separated by the English Channel. Our data suggest a stepwise pattern of expansion, dependent on available coastal habitat. The conservation implications are a need to protect local populations isolated by an expanse of deep water, and in particular, a population along the British coasts and in the North Sea as separate from the North Norway-Barents Sea population. It is also evident that overall diversity was reduced, probably during the last glacial epoch.