Historical accounts of sickle cell disease tend to draw a distinction between its theoretical role in catalyzing the postwar field of medical genetics or its clinical and social significance in representing the healthcare disparities experienced by African-Americans. This article bridges these theoretical-evolutionary and clinical-racial narratives by focusing on the discovery of sickle cells in marginalized Arabic-speaking communities of Yemen and Turkey in the 1950s. Like in North America, sickle cell research in the Middle East unfolded along the fractured social politics of race. I analyze how British, Turkish, and Arab geneticists attempted to create evolutionary hypotheses that reconciled historical and sociological boundaries between white and African, Arab and Turk. As the parameters of Turkish and Arab nationalism shifted in the Cold War-era Middle East, so did the favored explanatory narratives for the presence of sickle cells in different communities, which assigned different degrees of importance to African ancestry, socially enforced endogamy, and evolutionary adaptations to malaria.