Evolution of Metabolic Dependency (IMAGE) Max Planck Institute for Chemical Ecology Caption Natural selection drives the evolution of metabolic dependency. Initially metabolically autonomous populations of the bacterium Escherichia coli (left panel) diversify into two genetically distinct populations (right panel): one which retains the entire suite of biosynthetic capabilities (complete cells) and another, that loses these functions (open cells). The latter populations (open cells) thus coexist, and become metabolically dependent on the autonomous populations for the supply of key cellular building blocks like amino acids (triangle, circle and square). Credit Glen D'Souza, Christian Kost / Max Planck Institute for Chemical Ecology 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.