PLANT AND ANIMAL SCIENCES
BY FRANCISCO J. AYALA Department of Ecology and Evolutionary Biology University of California Irvine, Calif.
" The great lakes of Africa each contain a unique radiation of cichlids. Lake Tanganyika has more than 140 endemic species, Lake Victoria more than 200, and Lake Malawi about 500. Around 1960, the Nile perch, a piscivorous fish, was introduced in Lake Victoria in order to improve the fisheries, but it has eaten its way through much of the lake and caused a dramatic decrease in the number of species and fish biomass in the lake. This should provide a clear warning against the proposed introduction of exotic fish in Lake Malawi.
DJ. Miller, “Introductions and extinction of fish in the African great lakes,” Trends in Ecology and Evolution, 4,56-8, February 1989.
" Genetic diversity is very high among natural clones of the soil bacterium Pseudomonas cepacia,...