Frequencies of protan and deutan alleles in some Israeli communities and a note on the selection‐relaxation hypothesis

Anomaloscopic diagnoses of red‐green vision defects are reported and compared to the Ishihara tests for six Israeli populations. The highest frequencies of defects, about 10%, were found in an Arab sample and among Ashkenazi Jews; the lowest — about 4% — among Yemenite Jews. Heterogeneity was also found regarding the relative frequencies of the different alleles; these differences are due primarily to alleles causing milder defects (particularly deuteranomaly) while frequencies of anopias are rather similar. It seems that the same phenomenon prevails for other population differences as well. These findings are discussed in relation to the hypothesis that present‐day high rates of colorblindness in some populations may be explained by the relaxation of selection pressure against colorblindness.