A 25,000‐year history for Lake Victoria, East Africa, and some comments on its significance for the evolution of cichlid fishes

SUMMARY. 1. Microfossil and X‐ray analyses of sediment cores from Lake Victoria. East Africa, reveal a history of dramatically shifting environmental conditions over the last 25,000 years. 2. The diatom record of a 10 m core collected from beneath 66 m of water at an offshore station extends the known history of the lake 10,000 years beyond the published records from Pilkington Bay and Damba Channel, and shows that maximal late Pleistocene aridity occurred between 15,000 and 13,000 bp. Lack of precipitated carbonates in the offshore sediments suggests that the lake remained relatively dilute throughout the period of record. 3. There is no evidence that the lake level fell low enough to confine fishes to refugia in small isolated ponds or around river mouths.