the lake dried up completely about 12,400 years ago. This means that the rate of speciation of cichlid fishes has been extremely rapid: something on average of one new species every 40 years!
Nah; wrong conclusion. The Rift Valley Game & Fish Commission wildlife biologists drained the lake to eradicate undesirable species, then restocked it with 300 species of cichlids that were endangered elsewhere. *<];-')