MONOPHYLETIC ORIGIN OF LAKE VICTORIA CICHLID FISHES SUGGESTED BY MITOCHONDRIAL-DNA SEQUENCES

LAKE Victoria, together with its satellite lakes, harbours roughly 200 endemic forms of cichlid fishes that are classified as 'haplo-chromines'1,2 and yet the lake system is less than a million years old. This 'flock' has attracted attention because of the possibility that it evolved within the lake from one ancestral species3 and that biologists are thus presented with a case of explosive evolution. Within the past decade, however, morphology has increasingly emphasized the view that the flock may be polyphyletic4,5. We sequenced up to 803 base pairs of mitochondrial DNA from 14 representative Victorian species and 23 additional African species. © 1990 Nature Publishing Group.