Adaptation, extinction and global change

Research in our lab focuses on how populations become adapted to changing environments. In particular, if conditions become too stressful a population must either adapt by natural selection or become extinct. We need to know more about the process of "evolutionary rescue" in order to understand and predict how populations will respond to rapid environmental change. I propose three main areas of inquiry. The first concerns the variability of natural environments and the pattern of selection it creates. I shall develop wild yeast as a general model system for ecology and evolution in order to use the power of yeast genomic technology to study evolutionary change in natural populations. Secondly, I will conduct selection experiments in the laboratory to find out whether a population is likely to adapt to a given stress. These experiments use microbial populations that turn over very rapidly in order to study "evolution in real time". Whether they adapt should depend on the magnitude of the stress and on the genetic variation present in the population. Finally, I shall discover how phytoplankton, which are responsible for a large fraction of global primary production, will respond to elevated levels of carbon dioxide. This will also involve laboratory experiments using unicellular algae, to find out how individual species adapt over several hundred generations, and also how the species composition of whole communities changes. We need to understand these processes in order to predict how ecosystems will respond to global change in the course of the next century. Experimental evolution is a powerful way of both investigating general principles and probing the future of natural populations and communities.