The contribution of time and local geography to craniofacial variation in Nubia's Batn el Hajar.

While the history of Lower Nubia has traditionally been explained in terms of racial migrations and mixture, recent studies of craniofacial variation have emphasized the biological continuity in Lower Nubia over the past 12,000 years. Carlson and Van Gerven for example have demonstrated a trend among the populations for changes in craniofacial form that are best explained by changing masticatory function and in situ evolution independent of major racial migrations. The purpose of the present research is to extend the analysis of craniofacial variation in Lower Nubia to a culturally and geographically distinctive region to the south known as the Batn el Hajar. Data for Lower Nubia were obtained in the field from 44 Meroitic, 94 X-Group, and 36 Christian crania during the 1964 Colorado Expedition to Nubia. Data from the Batn el Hajar were obtained from 188 crania excavated in 1979 at the Christian site of Kulubnarti which spans the entire Christian era from 550 to 1450+. Analysis of 12 metric variables using discriminant function revealed two sources of variation. The first is temporal and reflects the pattern of facial reduction previously reported for Lower Nubia. The second is geographic and suggests a morphological convergence between the people of Kulubnarti and Lower Nubia during late Christian times. This convergence reflects the southward migration of Lower Nubian Christians following the annexation of Lower Nubia by Islamic Egypt in the middle 15th century.