How does seasonal migration influence genetic migration? Testing the evolutionary consequences of a widespread life history adaptation in a species assemblage of boreal birds

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

One of the most important processes in animal ecology and evolution is dispersal, the movement of individuals from the places where they are born to the places where they first reproduce. Dispersal is important for evolution because it influences how much populations found in different places exchange genes (gene flow), and therefore whether they will evolve into different species or stay connected as one. However, dispersal is difficult to study and poorly understood owing to the difficulty of tracking small animals. Migratory birds, for example, undergo staggering round trip migrations each year, but it remains unclear how these migratory movements influence the movement of genes between populations. This research uses genomic tools and migration tracking tags to investigate the dynamics of gene flow in migratory birds. In so doing, the research will shed light on how and why long-distance migration evolved. The project will develop a multimedia public exhibit at a natural history museum that explores the biology of migration and the threats facing migratory birds. The researchers will also convene a workshop to address how migratory bird deaths from building collisions can be mitigated and how data from bird building collisions can be used for scientific and conservation purposes. Finally, the proposed research will facilitate experiential learning opportunities for students to track migratory birds. The research will interrogate the relationship between seasonal migration—a widespread life history adaptation for seasonal environments—and genetic migration—the movement of genes that underlies population differentiation. Seasonal migration has long been thought to influence dispersal and therefore gene flow, but whether long-distance seasonal migration promotes versus constrains gene flow remains poorly understood. This proposal uses a novel comparative framework coupled with population genomics to test competing hypotheses on the influence of seasonal migration on gene flow. Using whole genome sequencing, the researchers will measure intraspecific genomic differentiation across the breeding ranges of each of 32 co-distributed bird species that breed in North American boreal forest. These species vary in their winter locations and thus their migration distances—distances that will be measured by tracking individuals with light-level geolocators. The researchers will then use phylogenetic comparative methods to assess the relationship between genetic differentiation, migration distance and other key traits. The project will advance understanding of how variation in life history influences species’ evolutionary trajectories of population genetic differentiation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.