People living in the Ganges Delta, where cholera is an ancient, endemic and often lethal disease, have adapted genetically to the scourge through variations in about 300 genes, say researchers who have scanned their genomes for the fingerprints of evolution. Regina C. LaRocque, HMS assistant professor of medicine at Massachusetts General Hospital, is an author of the study. John Mekalanos, chair of the Department of Microbiology and Immunobiology and the Adele Lehman Professor of Microbiology at HMS, is also quoted.