Institute of Anthropology, University of Zurich, 8057, Zurich, Switzerland.
Centre for Ecological and Evolutionary Synthesis, University of Oslo, 0316, Oslo, Norway.
Proc Natl Acad Sci U S A. 2022 May 24;119(21):e2113936119. doi: 10.1073/pnas.2113936119. Epub 2022 May 17.
The evolutionary history of African hunter-gatherers holds key insights into modern human diversity. Here, we combine ethnographic and genetic data on Central African hunter-gatherers (CAHG) to show that their current distribution and density are explained by ecology rather than by a displacement to marginal habitats due to recent farming expansions, as commonly assumed. We also estimate the range of hunter-gatherer presence across Central Africa over the past 120,000 years using paleoclimatic reconstructions, which were statistically validated by our newly compiled dataset of dated archaeological sites. Finally, we show that genomic estimates of divergence times between CAHG groups match our ecological estimates of periods favoring population splits, and that recoveries of connectivity would have facilitated subsequent gene flow. Our results reveal that CAHG stem from a deep history of partially connected populations. This form of sociality allowed the coexistence of relatively large effective population sizes and local differentiation, with important implications for the evolution of genetic and cultural diversity in Homo sapiens.
非洲狩猎采集者的进化历史为现代人类多样性提供了重要的见解。在这里，我们结合了中非狩猎采集者（CAHG）的民族志和遗传数据，表明他们目前的分布和密度是由生态环境决定的，而不是由于最近农业扩张而被迫迁移到边缘生境，这与普遍的假设相反。我们还使用古气候重建来估计过去 12 万年中非地区狩猎采集者的存在范围，我们新编制的年代考古遗址数据集通过统计验证了这一范围。最后，我们表明，CAHG 群体之间的基因组分歧时间估计与我们对有利于种群分裂的时期的生态估计相匹配，并且连通性的恢复将促进随后的基因流动。我们的研究结果表明，CAHG 源自一个具有部分连通人口的深远历史。这种形式的社会结构允许相对较大的有效种群大小和局部分化共存，这对智人遗传和文化多样性的进化具有重要意义。
