Abstract
Using whole genome re-sequencing data we study population level
associations with regional climate data and predict the response to
future climate change in populations of cold-adapted grouse species from
the Holarctic: rock ptarmigan (Lagopus muta), willow ptarmigan (L.
lagopus), and red grouse (L. scotica). We infer the relationships among
multiple regional populations of these species and examine their
individual adaptations to environmental factors, genetic offset (gap) in
the face of expected environmental change, and predict genes that may be
associated with climate risk. Genomic vulnerability to future climate
change scenarios (also known as offset or genetic gap) is predicted for
each of the populations in the context of predicted range contractions
under various global development scenarios. We show that different
regional populations have SNP distributions implying differentiated
influences of climatic parameters on predicted population-level
persistence. We find evidence of adaptation in all species towards local
annual temperature ranges and precipitation regimes. Ancestry
proportions derived from principal components analysis identified
genetic similarities between east and west Greenlandic populations of
rock Ptarmigan, all Scandinavian willow Ptarmigan, and red grouse in
England and Ireland. Based on our evidence of local adaptation, genetic
association with these climatic variables, and expected environmental
changes across the north Atlantic and Arctic, we suggest that general
warming and increased rainfall will be driving pressures on these
species with more stochastic weather patterns adding to threats against
more geographically isolated groups with greater risks at higher
latitudes.