Molecular and isotopic evidence for milk, meat, and plants in prehistoric eastern African herder food systems.

The development of pastoralism transformed human diets and societies in grasslands worldwide. The long-term success of cattle herding in Africa has been sustained by dynamic food systems, consumption of a broad range of primary and secondary livestock products, and the evolution of lactase persistence (LP), which allows digestion of lactose into adulthood and enables the milk-based, high-protein, low-calorie diets characteristic of contemporary pastoralists. Despite the presence of multiple alleles associated with LP in ancient and present-day eastern African populations, the contexts for selection for LP and the long-term development of pastoralist foodways in this region remain unclear. Pastoral Neolithic (c 5000 to 1200 BP) faunas indicate that herders relied on cattle, sheep, and goats and some hunting, but direct information on milk consumption, plant use, and broader culinary patterns is rare. Combined chemical and isotopic analysis of ceramic sherds (n = 125) from Pastoral Neolithic archaeological contexts in Kenya and Tanzania, using compound-specific δ13C and Δ13C values of the major fatty acids, provides chemical evidence for milk, meat, and plant processing by ancient herding societies in eastern Africa. These data provide the earliest direct evidence for milk product consumption and reveal a history of reliance on animal products and other nutrients, likely extracted through soups or stews, and plant foods. They document a 5,000-y temporal framework for eastern Africa pastoralist cuisines and cultural contexts for selection for alleles distinctive of LP in eastern Africa.

The bioarchaeology of mid-Holocene pastoralist cemeteries west of Lake Turkana, Kenya.

Early herders in eastern Africa built elaborate megalithic cemeteries ~ 5000 BP overlooking what is now Lake Turkana in northwestern Kenya. At least six 'pillar sites' were constructed during a time of rapid change: cattle, sheep, and goats were introduced to the basin as the lake was shrinking at the end of the African Humid Period. Cultural changes at this time include new lithic and ceramic technologies and the earliest monumentality in eastern Africa. Isolated human remains previously excavated from pillar sites east of Lake Turkana seemed to indicate that pillar site platforms were ossuaries for secondary burials. Recent bioarchaeological excavations at four pillar sites west of the lake have now yielded ≥49 individuals, most from primary and some from secondary interments, challenging earlier interpretations. Here we describe the mortuary cavities, and burial contexts, and included items such as adornments from Lothagam North, Lothagam West, Manemanya, and Kalokol pillar sites. In doing so, we reassess previous hypotheses regarding pillar site construction, use, and inter-site variability. We also present the first osteological analyses of skeletons buried at these sites. Although the human remains are fragmentary, they are nevertheless informative about the sex, age, and body size of the deceased and give evidence for health and disease processes. Periosteal moulds of long bone midshafts (n = 34 elements) suggest patterns of terrestrial mobility. Pillar site deposits provide important new insights into early herder lifeways in eastern Africa and the impact of the transition to pastoralism on past human populations.

A monumental cemetery built by eastern Africa's first herders near Lake Turkana, Kenya.

Monumental architecture is a prime indicator of social complexity, because it requires many people to build a conspicuous structure commemorating shared beliefs. Examining monumentality in different environmental and economic settings can reveal diverse reasons for people to form larger social units and express unity through architectural display. In multiple areas of Africa, monumentality developed as mobile herders created large cemeteries and practiced other forms of commemoration. The motives for such behavior in sparsely populated, unpredictable landscapes may differ from well-studied cases of monumentality in predictable environments with sedentary populations. Here we report excavations and ground-penetrating radar surveys at the earliest and most massive monumental site in eastern Africa. Lothagam North Pillar Site was a communal cemetery near Lake Turkana (northwest Kenya) constructed 5,000 years ago by eastern Africa's earliest pastoralists. Inside a platform ringed by boulders, a 119.5-m2 mortuary cavity accommodated an estimated minimum of 580 individuals. People of diverse ages and both sexes were buried, and ornaments accompanied most individuals. There is no evidence for social stratification. The uncertainties of living on a "moving frontier" of early herding-exacerbated by dramatic environmental shifts-may have spurred people to strengthen social networks that could provide information and assistance. Lothagam North Pillar Site would have served as both an arena for interaction and a tangible reminder of shared identity.

Reconstructing Prehistoric African Population Structure.

We assembled genome-wide data from 16 prehistoric Africans. We show that the anciently divergent lineage that comprises the primary ancestry of the southern African San had a wider distribution in the past, contributing approximately two-thirds of the ancestry of Malawi hunter-gatherers ∼8,100-2,500 years ago and approximately one-third of the ancestry of Tanzanian hunter-gatherers ∼1,400 years ago. We document how the spread of farmers from western Africa involved complete replacement of local hunter-gatherers in some regions, and we track the spread of herders by showing that the population of a ∼3,100-year-old pastoralist from Tanzania contributed ancestry to people from northeastern to southern Africa, including a ∼1,200-year-old southern African pastoralist. The deepest diversifications of African lineages were complex, involving either repeated gene flow among geographically disparate groups or a lineage more deeply diverging than that of the San contributing more to some western African populations than to others. We finally leverage ancient genomes to document episodes of natural selection in southern African populations. PAPERCLIP.