title: Reconstructing eight decades of genetic variation in an isolated Danish population of the large blue butterfly Maculinea arion.
abstract: BACKGROUND
  Fragmentation of terrestrial ecosystems has had detrimental effects on metapopulations of habitat specialists. Maculinea butterflies have been particularly affected because of their specialized lifecycles, requiring both specific food-plants and host-ants. However, the interaction between dispersal, effective population size, and long-term genetic erosion of these endangered butterflies remains unknown. Using non-destructive sampling, we investigated the genetic diversity of the last extant population of M. arion in Denmark, which experienced critically low numbers in the 1980s.
  
  
  RESULTS
  Using nine microsatellite markers, we show that the population is genetically impoverished compared to nearby populations in Sweden, but less so than monitoring programs suggested. Ten additional short repeat microsatellites were used to reconstruct changes in genetic diversity and population structure over the last 77 years from museum specimens. We also tested amplification efficiency in such historical samples as a function of repeat length and sample age. Low population numbers in the 1980s did not affect genetic diversity, but considerable turnover of alleles has characterized this population throughout the time-span of our analysis.
  
  
  CONCLUSIONS
  Our results suggest that M. arion is less sensitive to genetic erosion via population bottlenecks than previously thought, and that managing clusters of high quality habitat may be key for long-term conservation.
authors: Centre for Social Evolution, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark. line.ugelvig@ist.ac.at
authors: Line V
authors: LV
authors: Ugelvig
authors: Per S
authors: PS
authors: Nielsen
authors: Jacobus J
authors: JJ
authors: Boomsma
authors: David R
authors: DR
authors: Nash
mesh_terms: D000818:Animals; D002080:Butterflies / Q000145:classification* / Q000235:genetics*; D003718:Denmark; D017753:Ecosystem; D005260:Female; D014644:Genetic Variation; D008297:Male; D018895:Microsatellite Repeats; D011157:Population Dynamics