On Tuesday, June 18, Francesca Raffini, postdoctoral researcher at the Molecular Ecology Laboratory (University of Sheffield), will present, in a new session of the Café con Sal lecture series, the talk “Of snails, crabs and waves: a tale of adaptation through the lens of genomics”, in which she will discuss the different evolutionary forces responsible for the adaptive polymorphism of the rough periwinkle Littorina saxatilis, illustrating the factors and interactions that promote the speciation process in the presence of gene flow in natural populations.
Adaptation and speciation are very important processes as they determine biological diversity and its distribution across space and time. Speciation requires the evolution of barriers to gene flow between diverging populations. The mechanisms underlying these processes are largely unknown, particularly in cases of divergence in the presence of gene flow. A highly suitable study model for understanding the factors involved in adaptive divergence with gene flow is the snail L. saxatilis. This intertidal species has one ecotype adapted to strong wave action and another adapted to predation by crabs, and both are repeatedly found along the coast as a result of adaptive divergence. These ecotypes exhibit ecological, morphological, and behavioral divergence, yet they hybridize in the mid-intertidal zone where crab predation and wave exposure overlap.
Francesca Raffini, in collaboration with Professor Roger Butlin (University of Sheffield) and researchers from CIM-UVigo (including Professor Emilio Rolán-Alvarez and Dr. Juan Galindo), the University of Gothenburg, and the University of Sheffield, is conducting ecological field studies combined with genomic analysis (low coverage whole genome resequencing) of samples from the hybrid zone of L. saxatilis. Her main goal is to determine the genomic architecture of local adaptation of these ecotypes and the speciation in the presence of gene flow that is occurring in parallel along the coasts of Sweden and Galicia. The studies carried out at ECIMAT are part of the project “Insights from hybrid zones: testing for habitat choice, divergent selection and genomic architecture in Littorina saxatilis adaptive divergence,” funded by ASSEMBLE PLUS.
During her talk, Francesca will present preliminary results on phenotypic and genomic variation along the transects studied in the hybrid zone of L. saxatilis in Galicia, and she will also discuss the ecological field studies carried out during her stay at ECIMAT. The results obtained will improve our understanding of the role of environmental and genetic mechanisms in the speciation process, such as different types of selective forces, assortative mating, habitat choice, or genomic architecture.
The lecture will take place at 11.00h in the ECIMAT auditorium and will be broadcast live at http://tv.uvigo.es/es/directo/1.html, later being available on UVigoTV and on our website.
