Figure 2.

The Irish S. eubayanus isolates belong to the Holarctic clade. Unrooted maximum-likelihood tree of 89 S. eubayanus and two S. pastorianus strains was constructed with RAxML using the GTRGAMMA model of nucleotide substitution, using a concatenated SNP alignment of 319 298 SNP sites. Coloured shapes highlight distinct populations identified previously (Nespolo et al. 2020), and the two Irish (UCD) isolates are highlighted in bold. Most strain labels have been omitted for clarity (see Figure S1, Supporting Information). Branch colour denotes support values on a scale from 0 (red) to 100 (green). All branches in the Holarctic clade have a support value of 100. Support values < 100 are labelled in Figure 1 (Supporting Information).