Surveys of protein-coding sequences for evidence of positive selection in humans and chimpanzees have flagged surprisingly few genes known to be involved in neural or nutritional processes, despite the pronounced differences between humans and chimpanzees in behavior, cognition, and diet. It may be that most such differences are due to changes in gene regulation rather than protein structure. Here, we present the first survey of promoter (5'-flanking) regions, which are rich in _cis_-regulatory sequences, for signatures of positive selection in humans. Our results indicate that positive selection has targeted the regulation of many genes known to be involved in neural development and function, both in the brain and elsewhere in the nervous system,... |