Figure 2 mtDNA haplotype trees for indigobirds. Unrooted phylogenetic trees are shown for 118 indigobirds representing seven morphologically distinct species from Cameroon and Nigeria (a), and 98 indigobirds representing four species from southern Africa (b). Each circle represents an individual bird. Individuals within a box share the same haplotype. Each line segment represents a single nucleotide substitution, except for branches with cross-marks, which indicate multiple steps. Dotted lines show alternative connections present in one or more of the 3,264 and 1,288 equally parsimonious trees for the two data sets, respectively. One haplotype was found in both regions: the V. purpurascens haplotype in the lower right of b is identical to the common V. camerunensis haplotype in a.