Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Theory suggests that evolutionary changes, which are caused by both selection and genetic drift, should affect population-level absolute fitness and can thus potentially alter the dynamics of populations. Natural selection, which favors individuals having higher relative fitness, is typically expected to increase the average absolute fitness and population productivity. On the other hand, in some situations, natural/sexual selection is suggested to decrease population productivity and increase extinction risk, which is exemplified by cases such as the tragedy of the commons, evolutionary suicide or extinction. It has also been suggested that certain traits (e.g. sexual characters, selfishness, resistance to pathogens and self-reproduction) in particular are likely to directly affect the population performance, including productivity, density, stability, sustainability and population fitness, which in turn might affect extinction risk. Contaminating gene flow from populations with different environmental condition may also decrease population performance. The understanding of the side effects of evolution on demographic dynamics has only recently gained increasing research attention. However, the ecological (demographic) consequences of evolutionary changes and its underlying mechanisms have remained largely unexplored in natural populations. Here I am planning to investigate the demographic consequences of evolution of genetic diversity and its underlying mechanisms in various systems, including both animals and plants. Quantifying the role of evolutionary changes on overall population performance will increase our understanding of ecological dynamics including demography, range expansion, community dynamics, ecosystem function and extinction risk and elucidate how these processes in turn affect macroevolutionary dynamics.