The transition from hunting-gathering to agriculture in Nubia: dental evidence for and against selection, population continuity and discontinuity.

Some researchers posit population continuity between Late Palaeolithic hunter-gatherers of the late Pleistocene and Holocene agriculturalists from Lower (northern) Nubia, in northeast Africa. Substantial craniodental differences in these time-successive groups are suggested to result from in situ evolution. Specifically, these populations are considered a model example for subsistence-related selection worldwide in the transition to agriculture. Others question continuity, with findings indicating that the largely homogeneous Holocene populations differ significantly from late Pleistocene Lower Nubians. If the latter are representative of the local populace, post-Pleistocene discontinuity is implied. So who was ancestral to the Holocene agriculturalists? Dental morphological analyses of 18 samples (1075 individuals), including one dated to the 12th millennium BCE from Al Khiday, near the Upper Nubian border, may provide an answer. It is the first Late Palaeolithic sample (n = 55) recovered within the region in approximately 50 years. Using the Arizona State University Dental Anthropology System to record traits and multivariate statistics to estimate biological affinities, Al Khiday is comparable to several Holocene samples, yet also highly divergent from contemporaneous Lower Nubians. Thus, population continuity is indicated after all, but with late Pleistocene Upper-rather than Lower Nubians as originally suggested-assuming dental traits are adequate proxies for ancient DNA.