Structural variants underlie parallel adaptation following global invasion

Rapid adaptation during invasion has historically been considered limited and unpredictable. We leverage whole-genome sequencing of >2600 plants across six continents to investigate the relative roles of colonization history and adaptation during the worldwide invasion of Trifolium repens. Introduced populations contain high levels of genetic variation with independent colonization histories evident on different continents. Five large structural variants on three chromosomes exist as standing genetic variation within the native range, and exhibit strong signatures of parallel climate-associated adaptation across continents. Common gardens in the native and introduced ranges demonstrate that three structural variants exhibit patterns of selection consistent with local adaptation across each range. Our results provide strong evidence that rapid and parallel adaptation during invasion is caused by large-effect structural variants introduced throughout the world.

Methods
This dataset contains fitness data for 472 indviduals from four field common gardens located in the native and introduced ranges of Trifolium repens (white clover),  as described in the main text and methods of Battlay et al.. Briefly, seeds from 46 populations were collected along a latitudinal transect in North American by Lucas Albano and 47 populations were collected along a latitudinal transect in Western Europe by Simon Innes. Seeds from each of these populations were grown in a greenhouse refresher generation and crossed to other plants from the same population. The resulting lines were grown in four common gardens (Uppsula, Sweden; Montpellier, France; Mississauga, Canada; Lafayette, USA). The methods of Battlay et al. describes the fitness metrics measured for each individual. Tissue was taken for DNA extractions for each individual. Methods describing DNA extractions, library construction, and sequencing are described in the methods of Battlay et al..