Genetic history of a colonizing population: 'Drosophila buzzatii' (Diptera: Drosophilidae) in Australia

摘要: Drosophila buzzatii Patterson & Wheeler, a cactophilic species that feeds and breeds in the rotting tissues of various Opuntia cactus species, was inadvertently introduced to Australia from Argentina sometime during period 1931–1936. After bottleneck at introduction, its spread through distribution probably very rapid as result natural dispersal site introduction three other foci colonized by human intervention. By 1940, consequently D. buzzatii reduced spatially isolated populations, with probable further bottlenecking least some populations. Allozyme data (primarily six polymorphic loci) flies collected April 1972 February 1996 67 localities were used examine current population differentiation relationships, well infer aspects their demographic history. Although there is significant isolation-by-distance, genetic relationships among populations are not simply related geographical distance, implying drift has contributed differentiation. However, biotic and, an extent, physical environment same Argentina. Consequently, exposure novel environments led local adaptation Genetic variation structure Australian apparently determined founder effects (drift) level individual breeding sites (cactus rots), diversifying selection rots within locality, geographically varying localities. © 2013 The Linnean Society London, Biological Journal Society, 2013, 109, 682–698.