Additional file 1 of Phylogeographic history of flat periwinkles, Littorina fabalis and L. obtusata

Additional file 1: Figure S1. Maximum likelihood (ML) tree for the mitochondrial genes (COI and Cyt-b) concatenated (mtDNA dataset; 1200 bp). Numbers on branches represent bootstrap values equal to or over 80% for ML (left) and posterior probabilities equal to or over 0.90 for BI (right). The tree was rooted with L. saxatilis. Colors refer to lineages, roughly in agreement with geography. For L. fabalis, Iceland, Norway, Sweden, Shetlands are indicated in dark blue; UK, Ireland, France, in dark green; and Iberian Peninsula, in dark orange. For L. obusata, Iberian Peninsula is indicated in light orange and all remaining samples (USA, Iceland, Norway, Sweden, Shetlands, UK), in light blue. Putatively introgressed haplotypes between flat periwinkles are shown in black.