List of outlier genes identified using the ‘candidate SNP’ approach and their overlap among tetraploid lineages.

Candidate SNPs were used in the selection scan to identify positively selected genes (PSGs), following a three-step procedure. First, 1% outlier SNPs were identified; second, the top quartile of genes with the highest density of outlier SNPs were identified; and third, these genes were overlapped among the four tetraploid lineages of A. arenosa and A. lyrata to identify repeatedly differentiated genes. The PSGs and their overlap are shown here. (XLSX)