Hybridisation between land snails as a result of climate change

Molecular genetic studies have shown that hybridisation is much more common in animals than previously thought. Alleles are often exchanged between closely related species. Often the species remain separate despite the exchange of alleles. However, hybridisation can also lead to the merging of species or the formation of new species. The factors that influence evolutionary outcomes and the frequency of different outcomes are poorly understood.
Climate change leads to range shifts for many species. Such range shifts increase the likelihood that closely related species will encounter each other and thus the likelihood of hybridisation.

We investigate the effects of climate fluctuations during and after the ice ages on speciation processes. Door snails of the genus Charpentieria will be used as a model system. Some populations of this genus survived the glaciations in regions of the Southern Alps that were not covered by Alpine glaciers, and some populations survived south of the Alps. As a result of post-glacial climate warming and glacial retreat, the latter have spread back into the Alps, where they have encountered populations that survived the glacials in montane refugia. In some cases, the populations that were separated during the glaciations were already so differentiated that little hybridisation occurred, while in other cases hybridisation resulted in an almost continuous transition between previously isolated populations. We will use next-generation sequencing methods to investigate the genetic basis of the differentiation of the different populations and try to understand the genetic and environmental factors that led to the different evolutionary outcomes.

Project results

Xu, J. & Hausdorf, B. 2021. Repeated hybridisation increases diversity in the door snail complex Charpentieria itala in the Southern Alps. Mol. Phylogenet. Evol. 155: 106982.

Hausdorf, B. & Xu, J. 2023. Speciation of rock-dwelling snail species: disjunct ranges and mosaic patterns reveal the importance of long-distance dispersal in Chilostoma (Cingulifera) in the European Southern Alps. Mol. Phylogenet. Evol. 184: 107788.

Hausdorf, B., Xu, J. & Bamberger, S. 2024. Repeated colonisation of the Northern Alps from the Southern Alps by the rock-dwelling snail Cochlostoma henricae. Zool. Scripta.