The researchers will use new genomic approaches to study hybridization between native cutthroat trout and introduced rainbow trout in the northern Rocky Mountains. Their primary goal is to understand how genetic and evolutionary processes influence hybridization within and among populations. This research will transform our understanding of the spread of hybridization by combining laboratory description of genomic variation, study of fitness in the wild, and description of dispersal rates of native and hybridized individuals in complex landscapes. This work will test for the presence of certain chromosomal regions that spread rapidly among populations because of natural selection, and will also test if increased dispersal by hybrids accelerates the spread of hybridization.
Hybridization and species invasions provide exciting evolutionary experiments because natural selection on novel gene combinations can be studied in ecological time and in different environments. Hybridization between native and invasive species is one of the most serious threats to global biodiversity. The rate of hybridization is increasing with habitat degradation, translocations, and environmental change. Natural selection and dispersal by hybrids are thought to play key roles in the spread of hybridization. However, the mechanisms underlying this dramatic increase in hybridization and introgression remain unknown. These mechanisms can now be assessed using the application of thousands of genetic markers to assess the genomic basis of hybridization, fitness, and dispersal. The researchers have worked in collaboration for decades with tribal, state, and federal management agencies to conserve native cutthroat trout and protect them from hybridization with rainbow trout.
