Lake Malawi's Rocky Shores (IMAGE) Brown University Caption The water depth of Lake Malawi has fluctuated during the last 800,000 years. When its deep, there are more rocky shoreline habitats. Those niches could have driven the evolution of distinct cichlid species. Credit Andrew Cohen / University of Arizona Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.