Open AccessGenetic legacy from past panmixia: high genetic variability and low differentiation in disjunct populations of the E astern L arge H eath butterfly
Author(s) -
Louy Dirk,
Habel Jan Christian,
Abadjiev Stanislav,
Schmitt Thomas
Publication year - 2013
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/bij.12144
Subject(s) - biology , range (aeronautics) , genetic diversity , disjunct distribution , ecology , disjunct , panmixia , genetic structure , population , glacial period , biological dispersal , evolutionary biology , genetic variation , paleontology , materials science , demography , sociology , composite material , gene , phylogenetic tree , biochemistry
Glacial and interglacial cycles of the P leistocene have led to severe range fluctuations of many species. These range shifts of the past often are reflected by extant genetic signatures. Retractions of distribution areas often have fostered splits into several small and isolated retreats as remnants of the formerly interconnected range. These processes often go in line with losses of intraspecific diversity. By contrast, large and interconnected distribution ranges mostly sustain high levels of genetic variability. The genetic impact of both scenarios strongly depends on the temporal scale. In the present study, we tested the genetic effects of an assumed long‐lasting widespread distribution during glacial periods and more short‐term population retractions to mountain archipelagos during warm stages. We analyzed polymorphic allozymes for individuals of the E astern L arge H eath butterfly, C oenonympha rhodopensis , including major parts of its distribution, such as central I taly and the B alkan P eninsula. Our data show extraordinarily high genetic diversity. The only remarkable genetic split is detectable between the central A pennines ( I taly) and the B alkan mountain systems. The populations sampled over seven B alkan mountain systems ( J akupica, S har P lanina, O ssogovo, P irin, R ila, R hodopes, and S tara P lanina) show low genetic differentiation. This low genetic differentiation and high genetic diversity diverges from the genetic structures frequently found in species with disjunct distributions. We therefore hypothesize that the obtained molecular structure is the product of down‐slope shift during the last cold stage and subsequent expansion over the lowlands of the B alkan P eninsula. The current mountain restriction most probably occurred with the beginning of the postglacial warming, which is too short a time span to be of evolutionary relevance. Therefore, the recent high genetic diversities and low differentiation may still reflect long‐lasting glacial panmixia but not (yet) the recent disjunction. The strong genetic differentiation between the B alkans and I talian A pennines must result from an earlier dispersal process, most probably from the B alkans to I taly. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society , 2013, 110; , 281–290.