Local adaptation in an alpine finch, GWAS and FST output files

Understanding patterns and mechanisms underlying local adaptation is
becoming increasingly important for species conservation amid
anthropogenically driven environmental change. Alpine systems are
experiencing particularly intense pressure from environmental change
resulting from increased rates of warming and corresponding loss of snow
and ice. We integrate morphological and genetic analyses to identify
traits important for local adaptation in one of the highest elevation
breeding birds in North America, the Sierra Nevada Gray-crowned Rosy
Finch. We performed an in-depth analysis of how traits with known links to
thermoregulation in birds, such as wing length, bill size, and feather
microstructure, vary between two populations at sites with contrasting
climate and environmental conditions. We identified loci underlying these
traits using a genome-wide association study and further examined regions
of the genome related to altitude adaptation and cold tolerance using FST
outlier tests. Together, these results indicate that temperature, food
availability, and alpine landscape features may impose multifaceted and
potentially conflicting selective pressures on morphological traits
important to adaptation in alpine birds. Overall, this work represents one
of the first in-depth analyses of the genetic basis of adaptation in an
alpine specialist songbird.