Banguera-Hinestroza E.,Durham University |
Bjorge A.,Norwegian Institute of Marine Research |
Reid R.J.,United Road Services |
Jepson P.,Marine Mammal Stranding Research |
Hoelzel A.R.,Durham University
Conservation Genetics | Year: 2010
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. FST 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. © 2010 Springer Science+Business Media B.V.