Phylogenetic analysis of mtDNA control region haplotypes. Phylogenetic tree (best tree) inferred from mtDNA control region haplotypes using the maximum likelihood tool GARLI. Tree is rooted with the outgroup Lagenorhynchus acutus. ML bootstrap values (500 replicates) greater than 50% are denoted as the first number above supported nodes, NJ/Tamura-Nei bootstrap values (1000 replicates) greater than 50% are denoted as the second number. Supported nodes joining just a few terminal taxa only are not listed for clarity. Haplotypes of species denoted by an asterisk (*) group to monophyletic clades with bootstrap support greater than 50%. Arrows denote haplotypes that fall outside any coherent species clade.