NSF Postdoctoral Fellowship in Biology FY 2019: Population genomics of elevational range limits in Andean birds

Linck, Ethan B, Seattle WA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Research Using Biological Collections. The fellowship supports research and training of the fellow that will utilize biological collections in innovative ways. All species occur within a limited area known as their geographic range. Range limits can form without an obvious physical barrier because competition with other species prevents further expansion, because they are unable to adapt to a new environment, or because there are too few individuals of the same species to reproduce effectively. Many tropical organisms have narrow elevational ranges, meaning they occur only for a short vertical distance on continuous mountain slopes. This allows many species to coexist in a small area, and is part of why the tropics have so many species. However, we know relatively little about what determines elevational ranges in the tropics. The fellow will use DNA sequence data from extensive museum collections of Andean birds to understand the role of evolutionary and ecological processes in forming range limits. By understanding how these processes interact, we can better predict how species will respond to human induced environmental change. This has broad implications for biodiversity conservation and human health as endangered species and new diseases experience a warming world. The fellow will evaluate alternate hypotheses for species range limits by comparing the spatial distribution of genetic variation of tropical songbird species that have either narrow (<1500 m) or broad (>3000 m) elevational ranges. Using dense geographic sampling in extant biological collections from the Peruvian Andes, he will generate genome-wide DNA sequence data from across the full elevational ranges of 8 phylogenetically independent lineages. Each lineage will contain both elevational specialist and elevational generalist species. He will first use these data to identify the evolutionary and ecological processes that determine elevational ranges in Andean birds. Comparing observed patterns with predictions validated by simulations, he will evaluate the relative contribution of decreasing effective population size, biotic interactions, and migration from maladapted populations to the formation of equilibrium range limits. He will then test whether functional variation in hemoglobin is a prerequisite for elevational range expansion, and characterize whether adaptive variants have undergone hard or soft selective sweeps. During his postdoctoral research, the fellow will undergo training in museum curation and biodiversity informatics, advanced statistical genomics, and functional genetics. The research will be based at University of New Mexico, a majority-minority R1 institution, where the fellow will serve as a mentor in a training program for underrepresented students interested in research careers. 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.