A central aim of ongoing speciation research is to identify, quantify and understand the underlying mechanisms of different barriers to gene flow. Because such barriers and their sequence can be complex, a broad range of species need to be studied to understand general patterns of the speciation context. There are many possibilities to work on this topic as a potential Master thesis, either on Erebia butterflies or Arabidopsis plants.

Speciation and the role of different barriers to gene flow in Erebia butterflies

Erebia butterflies account for ~10% of diurnal butterfly species in Switzerland. Many species occupy different niches and in the case of the Erebia tyndarus  species complex, speciation captures different stages, i.e. species with strong intrinsic barriers and species without. Ongoing gene flow in part of the natural distribution allows us to study speciation in action.

=> Associated Master Project - Ecological differentiation in Erebia butterflies

Using stable isotopes you will test if and to which degree different Erebia species are ecologically differentiated in their trophic niche. The data can be combined with genomic and phenotypic data to test different speciation scenarios. Send an email to for further questions.

Contact zone between E. tyndarus and E. nivalis in the Alps.

Can the evolution of intrinsic barrier promote postglacial ecotype formation?

Species from temperate environments frequently evolved distinctly adapted ecotypes during post-glacial range expansion, where gene flow between ecotypes is often still possible due to the lack of intrinsic barriers. I study the effects of intrinsic barriers onto the genomic architecture of substrate associated ecotype formation in Arabidopsis lyrata. The latter provides an exceptional study system as A. lyrata not only underwent a postglacial range expansion, colonizing different substrates, but also occasionally evolved intrinsic barriers on the same time scale.

=> Associated Master Project - The strength of selfing as an intrinsic barrier

Using experimental and genomic approaches you will assess the strength of reproductive isolation between selfing and outcrossing populations and species and to understand the evolution of selfing itself. Send an email to for further questions.

                        Arabidopsis lyrata from a rock (left) and a sand (right) substrate