Phylogeography and recent historical biogeography of
Abstract:The genetic relationships of populations of the diving beetle Hydroporus glabriusculus in the British Isles and Sweden were examined using allozyme electrophoresis. H. glabriusculus is widespread in the far north of Eurasia, and occurs further south in western and central Europe as isolated relict colonies in fens whose development dates back to the early Postglacial. Study of genetic distance data reveals that the relict colonies of this insect in the British Isles do not form a distinct phylogeographic lineage, but instead belong to a number of separate groups, one of which also occurs in Sweden. Beetles from Ireland, Scotland and Norfolk appear to have diverged from each other during the Pleistocene, and colonized the British Isles in the early Postglacial in separate waves. Populations in the Norfolk Breck are closely related to the Swedish population studied, these two groups apparently having diverged during the Windermere Interstadial. All Norfolk colonies show remarkably similar depauperate levels of genetic variability, which is considered to have resulted from bottlenecking of an ancestral populaton in the Late Glacial. This study demonstrates that the recent historical biogeography of the biota of north‐west Europe may be more complex than would appear from a simple consideraton of Holocene events.
Document Type: Original Article
Affiliations: Department of Biology, Royal Holloway and Bedford New College, University of London, Egham, Surrey, U.K.
Publication date: March 1, 1994