Magill Clayton R, Ashley Gail M, Domínguez-Rodrigo Manuel, Freeman Katherine H
Geological Institute, ETH Zürich, Zurich 8092, Switzerland;
Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854;
Proc Natl Acad Sci U S A. 2016 Mar 15;113(11):2874-9. doi: 10.1073/pnas.1507055113. Epub 2016 Feb 22.
The availability of plants and freshwater shapes the diets and social behavior of chimpanzees, our closest living relative. However, limited evidence about the spatial relationships shared between ancestral human (hominin) remains, edible resources, refuge, and freshwater leaves the influence of local resources on our species' evolution open to debate. Exceptionally well-preserved organic geochemical fossils--biomarkers--preserved in a soil horizon resolve different plant communities at meter scales across a contiguous 25,000 m(2) archaeological land surface at Olduvai Gorge from about 2 Ma. Biomarkers reveal hominins had access to aquatic plants and protective woods in a patchwork landscape, which included a spring-fed wetland near a woodland that both were surrounded by open grassland. Numerous cut-marked animal bones are located within the wooded area, and within meters of wetland vegetation delineated by biomarkers for ferns and sedges. Taken together, plant biomarkers, clustered bone debris, and hominin remains define a clear spatial pattern that places animal butchery amid the refuge of an isolated forest patch and near freshwater with diverse edible resources.
植物和淡水的可获取性塑造了黑猩猩的饮食和社会行为，黑猩猩是与我们亲缘关系最近的现存物种。然而，关于人类祖先（人亚科原人）遗骸、可食用资源、避难所和淡水之间空间关系的证据有限，使得当地资源对我们物种进化的影响仍存在争议。保存在一个土壤层中的保存异常完好的有机地球化学化石——生物标志物，揭示了约200万年前在奥杜威峡谷一片连续25000平方米的考古地表上，米级尺度上不同的植物群落。生物标志物显示，在一个拼凑而成的景观中，人亚科原人能够获取水生植物和防护性树林，该景观包括一片林地附近由泉水滋养的湿地，二者均被开阔草地环绕。许多带有切割痕迹的动物骨骼位于林区内，以及由蕨类植物和莎草的生物标志物勾勒出的湿地植被几米范围内。综合来看，植物生物标志物、聚集的骨骼碎片和人亚科原人遗骸定义了一种清晰的空间模式，即将动物屠宰行为置于一片孤立森林区域的避难所内，且靠近拥有各种可食用资源的淡水区域。
