where nutritional levels are low. Previc emphasizes the contribution of nutritional factors to elevations of dopaminergic activity in the brain, which may have been responsible for the evolution of human intelligence since dopamine is crucial to working memory, cognitive shifting, abstract, distant concepts, and other hallmarks of advanced intelligence. See also Behavioral modernity Cetacean intelligence Cephalopod intelligence Denisovan Human evolution Human intelligence Primate cognition Timeline of human evolution References Bundled references Further reading Int Human evolution Intelligence Articles which contain graphical timelines