To define the people's origin more specifically, Parfitt and others developed a larger study to compare additional Lemba subjects (for whom clans were recorded) with males from South Arabia and Africa, as well as Ashkenazi and Sephardi Jews. They found significant similarities between the markers of the Lemba and men of the Ḥaḍramawt in Yemen. They also learned that the population in Yemen was relatively recent, so would not have shared common ancestors with those of the Lemba.