title: Incidence of colourblindness among four endogamous nomadic groups: an example of natural selection.
mesh_terms: D003117:Color Vision Defects / Q000235:genetics*; D005006:Ethnicity; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007178:Inbreeding; D007194:India; D008297:Male; D008393:Marriage; D012641:Selection, Genetic