Population genomic and historical analysis suggests a global invasion by bridgehead processes in Mimulus guttatus

• Published in: Communications Biology
• Main Authors: Vallejo-Marín, Mario, Friedman, Jannice, Twyford, Alex D, Lepais, Olivier, Ickert-Bond, Stefanie M, Streisfeld, Matthew A, Yant, Levi, van Kleunen, Mark, Rotter, Michael C, Puzey, Joshua R
• Other Authors: National Geographic Society, Biological and Environmental Sciences, Queen's University Kingston, University of Edinburgh, University of Bordeaux, University of Alaska Fairbanks, University of Oregon, University of Nottingham, University of Konstanz, Northern Arizona University, College of William and Mary, orcid:0000-0002-5663-8025
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Nature 2021
• Subjects: Plant evolution; Population genetics; Pacific; Alaska; Aleutian Islands
• Online Access: http://hdl.handle.net/1893/32464; https://doi.org/10.1038/s42003-021-01795-x; http://dspace.stir.ac.uk/bitstream/1893/32464/1/s42003-021-01795-x.pdf

Imperfect historical records and complex demographic histories present challenges for reconstructing the history of biological invasions. Here, we combine historical records, extensive worldwide and genome-wide sampling, and demographic analyses to investigate the global invasion of Mimulus guttatus from North America to Europe and the Southwest Pacific. By sampling 521 plants from 158 native and introduced populations genotyped at >44,000 loci, we determined that invasive M. guttatus was first likely introduced to the British Isles from the Aleutian Islands (Alaska), followed by admixture from multiple parts of the native range. We hypothesise that populations in the British Isles then served as a bridgehead for vanguard invasions worldwide. Our results emphasise the highly admixed nature of introduced M. guttatus and demonstrate the potential of introduced populations to serve as sources of secondary admixture, producing novel hybrids. Unravelling the history of biological invasions provides a starting point to understand how invasive populations adapt to novel environments.