Natural range expansion and human-assisted introduction leave different genetic signatures in a hermaphroditic freshwater snail

作者：Kopp Kirstin C^*; Wolff Kirsten; Jokela Jukka

来源：Evolutionary Ecology, 2012, 26(3): 483-498.

DOI：10.1007/s10682-011-9504-8

• Colonization
• Range expansion
• Invasion
• Genetic drift
• Lymnaea stagnalis
• Gastropod

Colonization events like range expansion or biological invasions can be associated with population bottlenecks. Small population size may lead to loss of genetic diversity due to random genetic drift, to loss of heterozygosity due to increased inbreeding and should leave a signature on the genetic polymorphism and genetic structure of populations. The mating system might additionally influence the outcome of such a process. Here, we compare invasive and native populations of the hermaphroditic freshwater snail Lymnaea stagnalis. In the native range we included populations that were ice-free during the last glaciation period and populations that were glaciated and are located at the edge of the species%26apos; native distribution range. The microsatellite data show substantial loss of genetic variation in the introduced range and no signs of high propagule pressure or admixture. The expressed polymorphism was so low that mating system analysis was not possible. In the native region, all populations display strong levels of differentiation (global F (ST): 0.341) independent of colonization history and exhibit no significant pattern of inbreeding. However, the populations in more recently colonized habitats show diminished genetic diversity. Overall, these results illustrate how dramatic the reduction in genetic diversity can be for hermaphroditic animals and that gene flow in the native range can be surprisingly low despite short distances.

• 出版日期2012-5