Document Type



The completed reproductive performance of 719 Sephardic Jewish couples married in Gibraltar from 1820 to 1939 is examined in detail. An examination of‘reproductive success’ revealed that only 24.7% of the children produced over the study period actually participated in the breeding structure of the Sephardic community of Gibraltar. ‘Non-successful’ components of reproductive performance were identified and discussed. Emigration and record-linking difficulties constituted the single most important component of non-successful reproduction observed among the Jews of Gibraltar. The evolutionary implications of the fertility differentials observed among the Jews are discussed in light of the results yielded from a modified approach to Crow’s Index of Total Selection Intensity. Two of the cultural factors identified here as having potential biological import are celibacy and governmental regulations regarding permanent residency in Gibraltar.