“…Classic population genetics theory states that de novo mutations are the raw source of genetic adaptation (Barton, 1998; Kaplan, Hudson, & Langley, 1989; Smith & Haigh, 1974) for which empirical evidence has been previously reported (e.g., Linnen, Kingsley, Jensen, & Hoekstra, 2009). Nevertheless, increasing evidence suggests that standing genetic variation plays a central role in adaptation (Bitter, Kapsenberg, Gattuso, & Pfister, 2019; Haenel, Roesti, Moser, MacColl, & Berner, 2019; Jones et al., 2012; Lai et al, 2019) and might allow faster adaptation to a new environment than de novo mutation (Barrett & Schluter, 2008). Finally, adaptive introgression may also contribute to local adaptation when new mutants or variants from standing genetic variation with beneficial effects on fitness are introduced in the population through interbreeding with related taxa (Hedrick, 2013; Oziolor et al., 2019; Racimo, Sankararaman, Nielsen, & Huerta‐Sánchez, 2015).…”