Fig. 5

Haplotype networks in Arabidopsis lyrata produced by the Pegas R package [60] for RPM1 (a, b, c) and WRR4 (d, e, f) with circles either unscaled (a, d) or scaled by relative frequency (b, c, e, f). Black circles indicate European haplotypes and grey indicates North American (in a and d); coloured circles indicate different countries (A. l. petraea) or sampling sites (A. l. lyrata) in the other plots. N indicates the number of sequences included. The RPM1 haplotype shared between European and Great Lakes samples (‘Haplotype 8’; Additional file 1: Table S6a) is indicated as ‘Hap 8’ in b) and c). In d) the black and grey arrows denote the most frequent haplotype as observed in Europe and Great Lakes respectively