Comparison of cox1 and its2 Neighbour-Joining trees for Bulinus. Comparison of Neighbour-Joining trees for cox1 and its2 data (cox1 – 1010 sites and its2 – 394 sites). Kimura 2-parameter distance has been used for cox1 and p-distance for its2. Substitutions include both transitions and transversions and 1000 bootstrap replicates have been performed. Bootstrap values below 50 are not shown. B. africanus group isolates are shown in red, B. forskalii in green, B. reticulatus in black and B. truncatus/tropicu s in blue. See Table 1 for origins of isolates.