Abstract
The marine snail Littorina saxatilis is a common inhabitant of intertidal shores of the north Atlantic. It is amazingly polymorphic and forms reproductively isolated ecotypes in microhabitats where crabs are either present and wave action is less furious, or where waves are strong and crabs are absent. Decades of research have unveiled much of the ecological and demographic context of the formation of crab- and wave-ecotype snails showing important phenotypic differences being inherited, differential selection being strong over adjacent microhabitats, local dispersal being restricted, and long-distance transports of individuals being rare. In addition, strong assortative mating of ecotypes has been shown to include a component of male mate preference based on female size. Several studies support ecotypes being diverged locally and under gene flow in a parallel and highly replicated fashion. The high level of replication at various levels of independence (from local to pan-European scale) provides excellent opportunities to investigate the detailed mechanisms of microevolution, including the formation of barriers to gene flow. Current investigations benefit from a draft reference genome and an integration of genomic approaches, modelling and experiments to unveil molecular and ecological components of speciation and their interactions.
Highlights
It is somewhat fascinating that in evolution we are still investigating the conceptual ideas that Darwin and his peers raised and discussed already 150 years ago
Starting from a confused taxonomy, the marine snail Littorina saxatilis has become an important model for evolutionary studies
Intertidal habitats have strong vertical gradients in many physical parameters and to find out if the genetic variation in L. saxatilis was to any extent affected by such gradients, we analysed allozyme variation in samples of wave ecotype over vertical shore gradients of 5–6 m in heavily exposed rocky shores in Sweden, the UK, Iceland and Norway
Summary
It is somewhat fascinating that in evolution we are still investigating the conceptual ideas that Darwin and his peers raised and discussed already 150 years ago. We are in the middle of a very exciting time when most biological research is profiting from new technologies (next-generation sequencing, computer-based data analyses and modelling), and these technologies will throw much new light on many of the classical questions that, by and large, remain the same. One such question is how new biodiversity, and in particular new species, is formed (the ‘mystery of mysteries’). As I have myself been heavily involved in this development, the review of this system will be a somewhat egocentric journey through much of my own scientific career. A journey that has given me some personal experiences with relevance to the discussion of gender in science (Box 1)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
