Minimum Evolution tree for Bulinus isolates using the complete cox1 fragment, transversions only. Minimum Evolution tree for the complete cox1 fragment (1009 sites) using Kimura 2-parameter distance and utilizing transversional substitutions only. 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.