Mechanisms of adaptive radiation

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Adaptive radiation is an episode in evolution during which new species originate rapidly from a common ancestor and evolve differences in diet, habitat, body size and shape, behavior and other traits. These episodes are thought to have given rise to much of life's diversity. Biologists have made outstanding progress over the last decade or two in understanding the general features of adaptive radiation, but many details of the underlying mechanisms are still obscure. Work in my lab addresses the causes of adaptive radiation in a species complex of threespine stickleback fish inhabiting young lakes and streams of coastal British Columbia. This group represents an evolutionary work-in-progress and it includes some of the youngest species on earth. It has many features make it amenable to research (it has been called a "supermodel" for evolutionary studies). Many changes in size, shape and behavior have evolved repeatedly in different lakes, and every stage in the evolution of reproductive isolation (traits that reduce gene flow between species -- a requirement for the evolution of new species) is represented. Yet, populations can be crossed in the lab, allowing genetic and experimental study. Substantial genetic resources have recently been developed for stickleback, including a complete genome sequence, making it one of the best systems known in which to investigate the genetic basis of evolution. The present proposal harnesses these advantages to investigate natural selection on genes, the genomic changes that underlie two stages in the origin and divergence of new species, and the effects that adaptive radiation has on ecosystems. The work expands collaborations with molecular biologists Drs. Kingsley (Stanford University Medical School) and Peichel (Fred Hutchinson Cancer Research Centre, Seattle) that have already yielded high-profile discoveries, open transfer of knowledge and tools, and advanced training of students.