Premium
Intraspecific molecular variation in the seaweed fly Coelopa frigida consistent with behavioural distinctness of British and Swedish populations
Author(s) -
MacDonald C.,
Brookfield J. F. Y.
Publication year - 2002
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1046/j.1365-294x.2002.01559.x
Subject(s) - biology , intraspecific competition , isolation by distance , phylogeography , genetic variation , population , evolutionary biology , ecology , local adaptation , adaptation (eye) , zoology , gene flow , genetics , phylogenetics , gene , demography , neuroscience , sociology
The major aim of this study was to compare the intraspecific variation and genetic structure of the behaviourally distinct British and Swedish populations of the seaweed fly Coelopa frigida . C. frigida has been the subject of intense study into the basis of female choice. The behaviour of British females is consistent with a ‘good genes’ model, whereas that of the Swedish flies suggests a Fisher process, in which the difference between the former and the latter is defined by female choice increasing offspring viability in ‘good genes’ models. Through a study of variability in the mitochondrial cytochrome oxidase II gene from more than 600 flies, we show that there is clear differentiation at the molecular level between the two countries’ populations, with an F ST of > 75% and no shared haplotypes. Tajima's test reveals an excess of rare variants relative to expectation, which, if not the result of selective sweep, indicates either a population expansion or purifying selection against weakly deleterious variants. Within the two populations, substantial subpopulation differentiation is observed in the UK, where there is also evidence of isolation by distance. Swedish populations exhibit lower variability, and no evidence of isolation by distance, with the latter result possibly being related to the continuous distribution of suitable habitat. The pattern of intraspecific variation is explainable by a combination of contemporary and also historical factors. British and Swedish populations may have been descended from at least two separate founding populations during the recolonization of these areas following Pleistocene glaciations.