Cebeiro Adela, Key Alastair
Department of Anthropology, New York University, New York, New York, USA.
Department of Archaeology, University of Cambridge, Cambridge, UK.
Am J Biol Anthropol. 2024 Mar;183(3):e24759. doi: 10.1002/ajpa.24759. Epub 2023 May 23.
Current evidence suggests that flaked stone tool technologies did not emerge until ~3.3-2.6 million-years-ago (Ma). It is often hypothesized that early hominin (principally Ardipithecus and early Australopithecus) manual anatomy may have prevented an earlier emergence, as the forceful precision grips essential to flake tool-use may have been ineffectively performed by these species. Marzke, Marchant, McGrew, and Reece (2015) observed potentially forceful pad-to-side precision grips being recruited by wild chimpanzees (Pan troglodytes) during feeding behaviors, indicating that Pan-like manual anatomy, and therefore potentially early hominin anatomy, may be capable of effectively securing flake stone tools during their use.
Here, we report on the grips recruited by four captive, human-trained, bonobos (Pan paniscus) during the use of stone and organic tools, including flake stone tools during cutting behaviors.
It is revealed that pad-to-side precision grips are frequently recruited by these bonobos when securing stone flakes during cutting actions. In some instances, high forces could have been resisted and applied by the thumb and fingers.
While our analyzes are preliminary and limited to captive individuals, and Pan is not suggested to secure flakes with the same efficacy as Homo or Australopithecus, it points to early hominins potentially being able to perform the precision grips required to use flake stone tools. In turn, the ability to gain tangible benefits from the effective use of flake tools (i.e., gain energetic returns from processing food resources) may have been - at least anatomically - possible in early Australopithecus and other pre-Early Stone Age hominin species. In turn, hominin manual anatomy may not be a leading restriction on the emergence of the earliest stone tool technologies.
目前的证据表明，片状石器技术直到约330万至260万年前才出现。人们常常假设，早期人类（主要是地猿和早期南方古猿）的手部解剖结构可能阻碍了其更早出现，因为这些物种可能无法有效地执行片状工具使用所必需的有力精确抓握。马尔兹克、马钱特、麦格鲁和里斯（2015年）观察到，野生黑猩猩（黑猩猩）在进食行为中会使用潜在有力的指腹对侧面精确抓握，这表明类似黑猩猩的手部解剖结构，因此也可能是早期人类的解剖结构，在使用片状石器时可能能够有效地固定工具。
在此，我们报告了四只人工饲养、经过人类训练的倭黑猩猩（倭黑猩猩）在使用石器和有机工具（包括切割行为中的片状石器）时所采用的抓握方式。
结果显示，这些倭黑猩猩在切割动作中固定石片时经常采用指腹对侧面精确抓握。在某些情况下，拇指和手指可能会抵抗并施加较大的力。
虽然我们的分析是初步的，且仅限于人工饲养的个体，并且并不认为倭黑猩猩固定石片的效率与人类或南方古猿相同，但这表明早期人类可能能够执行使用片状石器所需的精确抓握。反过来，至少在解剖学上有可能从有效使用片状工具中获得切实利益（即从加工食物资源中获得能量回报），这在早期南方古猿和其他早更新世石器时代之前的人类物种中是可能的。因此，人类的手部解剖结构可能不是最早石器技术出现的主要限制因素。
