Multiple lines of genetic and archaeological evidence suggest that there were major demographic changes in the terminal Late Pleistocene epoch and early Holocene epoch of sub-Saharan Africa1–4. Inferences about this period are challenging to make because demographic shifts in the past 5,000 years have obscured the structures of more ancient populations3,5. Here we present genome-wide ancient DNA data for six individuals from eastern and south-central Africa spanning the past approximately 18,000 years (doubling the time depth of sub-Saharan African ancient DNA), increase the data quality for 15 previously published ancient individuals and analyse these alongside data from 13 other published ancient individuals. The ancestry of the individuals in our study area can be modelled as a geographically structured mixture of three highly divergent source populations, probably reflecting Pleistocene interactions around 80–20 thousand years ago, including deeply diverged eastern and southern African lineages, plus a previously unappreciated ubiquitous distribution of ancestry that occurs in highest proportion today in central African rainforest hunter-gatherers. Once established, this structure remained highly stable, with limited long-range gene flow. These results provide a new line of genetic evidence in support of hypotheses that have emerged from archaeological analyses but remain contested, suggesting increasing regionalization at the end of the Pleistocene epoch.

OBJECTIVES: The aim of this study was to compare perceptions of body size in European, Maori and Paci®c Islands people with measured body mass index (BMI), waist-to-hip ratio and change in BMI since age 21 y. Socio-demographic factors that in¯uenced perceptions of body size were also investigated. DESIGN: Cross-sectional survey. METHODS: Participants were 5554 workers, aged ! 40 y, recruited from companies in New Zealand during 1988 ± 1990. RESULTS: Prevalences of BMI b 25 kgam 2 were: Europeans, 64.7% men, 47.2% women; Maori, 93.2% men, 80.6% women; and Paci®c Islanders, 94.1% men, 92.9% women. Similarly, prevalences of BMI b 30 kgam 2 were: Europeans, 14.4% men, 14.6% women; Maori, 55.0% men, 41.9% women; and Paci®c Islanders, 55.1% men, 71.7% women. At each perception of body size category, Maori and Paci®c Islands men and women had a higher BMI than European men and women, respectively. BMI increased with increasing perception of body size in all gender and ethnic groups. Since age 21, increases in BMI were highest in Paci®c Islands people and increased with increasing perceptions of body size category in all ethnic and gender groups. BMI adjusted odds (95% CI) of being in a lower perception category for body size were 1.70 (1.38 ± 2.12) in Maori and 8.99 (7.30 ± 11.09) in Paci®c people compared to Europeans, 1.27 (1.13 ± 1.42) times higher for people with no tertiary education, 1.41 (1.25 ± 1.59) times higher in people with low socioeconomic status, and 0.94 (0.92 ± 0.95) for change in BMI since age 21. CONCLUSION: Nutritional programs aimed at reducing levels of obesity should be ethnic-speci®c, addressing food and health in the context of their culture, and also take into account the socioeconomic status of the group. On the population level, obesity reduction programs may be more bene®cial if they are aimed at the maintenance of weight at age 21.

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