Department of Early Prehistory and Quaternary Ecology, Eberhard Karls University of Tübingen, Germany; Department of Archaeology, University of Cape Town, Rondebosch, 7701, South Africa.
Laboratory of Mass Spectrometry of Interactions and Systems (LSMIS), Strasbourg University, CNRS, CMC UMR 7140, France.
J Hum Evol. 2024 Sep;194:103578. doi: 10.1016/j.jhevol.2024.103578. Epub 2024 Aug 14.
The foragers of the southern African Middle Stone Age were among the first humans to adapt their environment and its resources to their needs. They heat-treated stone to alter its mechanical properties, transformed yellow colorants into red pigments and produced moldable adhesive substances from plants. Until now, only Podocarpus conifers have been identified as the botanical origin of Middle Stone Age adhesives. This is curious as these conifers do not produce sticky exudations that could be recognized as potential adhesives. To obtain an adhesive, tar must be made with a technical process based on fire. However, the nature of these technical processes has remained unknown, hampering our understanding of the meaning of this adhesive technology for the cultural evolution of early Homo sapiens. Here, we present the first evidence of a technique used for tar making in the Middle Stone Age. We created an experimental reference collection containing naturally available adhesives along manufactured tars from plants available in the Middle Stone Age and compared these to artifacts using gas chromatography-mass spectrometry and infrared spectroscopy. We found that, in the Howiesons Poort at Sibhudu Cave, tar was made by condensation, an efficient above-ground process. Even more surprisingly, the condensation method was not restricted to Podocarpus. The inhabitants of Sibhudu also produced tar from the leaves of other plants. These tars were then used, either without further transformation or were processed into ochre-based compound adhesives, suggesting that people needed different moldable substances with distinct mechanical properties. This has important implications for our understanding of Middle Stone Age H. sapiens, portraying them as skilled engineers who used and transformed their resources in a knowledgeable way.
南非中石器时代的采集者是最早根据自身需求来适应环境及其资源的人类之一。他们对石头进行热处理以改变其机械性能，将黄色颜料转化为红色颜料，并从植物中提取可塑的粘性物质。到目前为止，只有罗汉松科的针叶树被确定为中石器时代粘合剂的植物来源。这很奇怪，因为这些针叶树不会产生可被识别为潜在粘合剂的粘性分泌物。要获得粘合剂，焦油必须通过基于火的技术工艺制成。然而，这些技术工艺的性质仍然未知，这阻碍了我们理解这种粘合剂技术对早期智人文化进化的意义。在这里，我们首次提供了中石器时代用于制作焦油的技术的证据。我们创建了一个实验性参考集，其中包含了从中石器时代可获得的植物中提取的天然粘合剂和人造焦油，并使用气相色谱-质谱和红外光谱对这些粘合剂和人造焦油与文物进行了比较。我们发现，在 Sibhudu 洞穴的 Howiesons Poort，焦油是通过冷凝制成的，这是一种高效的地上工艺。更令人惊讶的是，冷凝法不仅限于罗汉松科。Sibhudu 的居民还从其他植物的叶子中提取焦油。然后，这些焦油要么未经进一步处理，要么被加工成基于赭石的复合粘合剂，这表明人们需要具有不同机械性能的不同可塑物质。这对我们理解中石器时代的智人具有重要意义，表明他们是熟练的工程师，以明智的方式使用和转化自己的资源。
