INSIGHTS INTO THE EXTENT OF HYBRIDIZATION BETWEEN FLAT PERIWINKLES IN THE IBERIAN PENINSULA

STUDENT SEMINAR IN BIODIVERSITY AND EVOLUTION

Understanding the interaction between divergent natural selection and gene flow during speciation is one of the main goals of evolutionary biology. The marine gastropods Littorina fabalis and L. obtusata offer an interesting system to study ecological speciation and to assess the impact of hybridization in reproductive isolation. Although introgressive hybridization between these two sister species was recently suggested, the extent to which it occurs is still unknown. Using genetic (microsatellite-based) and geometric-morphometrics (landmark-based) tools, we studied multiple locations representing different geographic contexts of divergence in North-western Iberian Peninsula shores, to assess the extent and patterns of hybridization between flat periwinkles. Results suggest that hybridization is not frequent in Iberian populations with a single exception in the North of Portugal. Moreover, the two species tend to present a more similar shell (shape and size) when in sympatry/parapatry than in allopatry, contrary to the expected signatures of character displacement/reinforcement. The potential impact of hybridization on the diversification of flat periwinkles will be discussed.

Diana Costa graduated in Biology in 2012, at the Faculty of Sciences, University of Porto. Diana’s main research interests encompass several topics in the field of evolutionary biology, such as the mechanisms of adaptation and speciation. To improve her skills and learn more about these topics, Diana enrolled the Masters in Biodiversity, Genetics and Evolution at CIBIO-InBIO in 2013. Her MSc thesis, in which this seminar is based, has been developed under the supervision of Rui Faria and co-supervision of Graciela Sotelo and Antigoni Kaliontzopoulou., in the scope of the POPGEN Group.

Image credits: Isabel Pintor