Final Activity Report Summary - ECOSPEC (Testing the predictions of ecological speciation in sticklebacks)
Why is life so diverse? This question has two parts: why are there so many species, and why do they look so different? The answer to the latter part is that species adapt to their local conditions, but might this adaptation also drive species formation? Even though this idea was first proposed by Darwin, many key hypotheses remain untested.
Our project tested three predictions from this process of 'ecological speciation'. First, can changes in mate preferences be driven by adaptation to a new environment? Second, does divergent natural selection act on the genes underlying locally adaptive traits? If so, movement of these genes between environments will be reduced. Third, can selection on a gene stop the surrounding DNA moving between environments, thereby allowing greater differentiation? These experiments will elucidate how adaptation can prevent interbreeding between differentially adapted populations and thus create new species.
We tested the above questions using the stickleback model system. These fish have repeatedly split into ecologically isolated species in Canadian lakes and rivers, and they are therefore a naturally replicated 'experiment' in species formation. Furthermore, excellent genomic resources are now available for these species. The project involved collaboration between the stickleback research unit at the University of British Columbia (Canada) and the population genetics group at the Centre for Functional Ecology and Evolution in Montpellier, France.
Our project contributed several key insights into our understanding of biodiversity: we found that adaptation can drive speciation by altering mate preferences, such that populations in different environments no longer recognise each other as potential mates. Furthermore, I found that parallel shape evolution does not necessarily imply parallel evolution at the genetic level, a result in contrast with the current opinion. I have also initiated a very large long term experiment to find the genetic loci responsible for fitness itself during adaptation to a new environment. This experiment is now in its final phase and the results will be available by the end of the year.
Lastly, I have developed a strong collaboration between my lab and a group of evolutionary physiologists, and together we are examining the evolution of physiological performance in stickleback populations.
Our project tested three predictions from this process of 'ecological speciation'. First, can changes in mate preferences be driven by adaptation to a new environment? Second, does divergent natural selection act on the genes underlying locally adaptive traits? If so, movement of these genes between environments will be reduced. Third, can selection on a gene stop the surrounding DNA moving between environments, thereby allowing greater differentiation? These experiments will elucidate how adaptation can prevent interbreeding between differentially adapted populations and thus create new species.
We tested the above questions using the stickleback model system. These fish have repeatedly split into ecologically isolated species in Canadian lakes and rivers, and they are therefore a naturally replicated 'experiment' in species formation. Furthermore, excellent genomic resources are now available for these species. The project involved collaboration between the stickleback research unit at the University of British Columbia (Canada) and the population genetics group at the Centre for Functional Ecology and Evolution in Montpellier, France.
Our project contributed several key insights into our understanding of biodiversity: we found that adaptation can drive speciation by altering mate preferences, such that populations in different environments no longer recognise each other as potential mates. Furthermore, I found that parallel shape evolution does not necessarily imply parallel evolution at the genetic level, a result in contrast with the current opinion. I have also initiated a very large long term experiment to find the genetic loci responsible for fitness itself during adaptation to a new environment. This experiment is now in its final phase and the results will be available by the end of the year.
Lastly, I have developed a strong collaboration between my lab and a group of evolutionary physiologists, and together we are examining the evolution of physiological performance in stickleback populations.