Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change

Background: Approximately two hundred human burials were discovered on the edge of a paleolake in Niger that providea uniquely preserved record of human occupation in the Sahara during the Holocene (,8000 B.C.E. to the present). CalledGobero, this suite of closely spaced sites chronicles the rapid pace of biosocial change in the southern Sahara in response tosevere climatic fluctuation.Methodology/Principal Findings: Two main occupational phases are identified that correspond with humid intervals in theearly and mid-Holocene, based on 78 direct AMS radiocarbon dates on human remains, fauna and artifacts, as well as 9 OSLdates on paleodune sand. The older occupants have craniofacial dimensions that demonstrate similarities with mid-Holocene occupants of the southern Sahara and Late Pleistocene to early Holocene inhabitants of the Maghreb. Theirhyperflexed burials compose the earliest cemetery in the Sahara dating to ,7500 B.C.E. These early occupants abandon thearea under arid conditions and, when humid conditions return ,4600 B.C.E., are replaced by a more gracile people withelaborated grave goods including animal bone and ivory ornaments.Conclusions/Significance: The principal significance of Gobero lies in its extraordinary human, faunal, and archaeologicalrecord, from which we conclude the following:(1) The early Holocene occupants at Gobero (7700–6200 B.C.E.) were largely sedentary hunter-fisher-gatherers withlakeside funerary sites that include the earliest recorded cemetery in the Sahara.(2) Principal components analysis of craniometric variables closely allies the early Holocene occupants at Gobero with askeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreband southern Sahara.(3) Gobero was abandoned during a period of severe aridification possibly as long as one millennium (6200–5200 B.C.E).(4) More gracile humans arrived in the mid-Holocene (5200–2500 B.C.E.) employing a diversified subsistence economybased on clams, fish, and savanna vertebrates as well as some cattle husbandry.(5) Population replacement after a harsh arid hiatus is the most likely explanation for the occupational sequence at Gobero.(6) We are just beginning