Analysis of museum specimens suggests extreme genetic drift in the adonis blue butterfly (Polyommatus bellargus)

摘要

We amplified microsatellite DNA from museum specimens over 100 years old of theadonis blue butterfly, Polyommatus bellargus. These results were compared withbutterfly samples taken from the same site near Folkestone in southern UK in1998/9, 200 generations later, and with samples from other extant UKpopulations. Dramatic changes in allele frequencies have occurred over time,which is indicative of substantial genetic drift or extinction/recolonization.Patterns of heterozygosity in the 1998/9 sample are indicative of a pastbottleneck, and one was known to have occurred in the late 1970s in this andmany other UK populations. One allele present at high frequency in 1896 was notdetected in any extant UK population, suggesting that it may have been lost fromthe UK (a ‘ghost’ allele), although the allele may well persist elsewhere withinthe range of the species. Although the present study is relatively small inscale (20 museum specimens from one site), it serves to reinforce the enormouspotential of museum specimens in well represented taxa such as butterflies forexamining the effects of demographic events spanning many ye