Format: ORAL

Amy L. Angert1, Daniel N. Anstett1-5,Julia Anstett6,7, Seema N. Sheth8, Dylan R. Moxley1, Mojtaba Jahani1, Kaichi Huang1, Marco Todesco1,9,10, Rebecca Jordan11, Jose Miguel Lazaro-Guevara1, Loren H. Rieseberg1

1 Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, Canada 2 Plant Resilience Institute, Michigan State University, East Lansing, USA 3 Department of Plant Biology, Michigan State University, East Lansing, USA 4 Department of Entomology, Michigan State University, East Lansing, USA 5 Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, USA ??6 Genomic Sciences and Technology Program, University of British Columbia, Vancouver, Canada 7 Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada 8 Department of Plant and Microbial Biology, North Carolina State University, Raleigh, USA 9 Michael Smith Laboratories, University of British Columbia, Vancouver, Canada 10 Department of Biology, University of British Columbia, Kelowna, Canada 11 CSIRO Environment, Sandy Bay, Australia

Populations declining due to extreme climate change may require adaptive evolutionary change in order to persist. While evolutionary rescue is well-established by theory and demonstrated in microbial experiments, its relevance to the persistence of natural populations facing climate change remains largely unknown. Here we document range-wide patterns of rapid evolution and evolutionary rescue in scarlet monkeyflower after an exceptional natural drought event in the western United States. We combine 10 years of field demographic monitoring with whole-genome sequencing across 55 populations prior to the exceptional drought (baseline genomics), and whole-genome resequencing of 12 populations throughout the drought (time series genomics). Range-wide population decline during the drought was most closely associated with precipitation anomalies. Genome-environment associations in baseline samples identify approximately 600 snigle-nucleotide polymorphisms associated with spatial variation in historical climate. In the time series samples, the heat- or drought-associated allele at these 600 climate-associated loci increased more than expected by chance throughout the drought, consistent with rapid evolution by natural selection. Finally, rates of demographic recovery were predicted by genetic variation, not climate anomalies. Specifically, populations that recovered most quickly had higher nucleotide diversity at climate-associated loci in the baseline samples and greater rates of temporal change in climate-associated loci in the time series samples. Genetic variation, rapid evolution, and demography showed weak latitudinal clines across the species range, with rear edge populations facing some of the steepest demographic declines, the lowest segregating genetic variation, and the weakest response to selection. These findings demonstrate evolutionary rescue in the wild, showing that some populations can evolve to recover from climate-change induced population decline and that genomics tools can have an important role in predicting recovery capacity via evolutionary rescue.