Human hand and chimpanzee hand6/12/2023 ![]() ( b) Human precision grip (shown, a five-jaw chuck precision grip) in which the pads of the thumb and fingers grasp and manipulate the object and ( c) a power squeeze grip, in which the fingers grasp the object diagonally and thumb is in line with the forearm. ( a) The suite of bony features typically considered distinct in the human hand (although some specific features are found in other primates, such as broad apical tufts in baboons) that reflect the ability to forcefully oppose the pads of the thumb and fingers, the well-developed musculature to the thumb and fifth digit, the high external loading of the thumb and distribution of that load across the wrist and palm, and the broad fingertips for control and manipulation of objects, especially within one hand. Therefore, this paper focuses on the more recent fossil and archaeological evidence and the results of new methodologies that are helping to broaden our understanding of the evolution of the human hand and, in particular, the potential manipulative abilities of early hominins and how these might also have been balanced with requirements of arboreal locomotion.īony and soft tissue morphology of the human hand considered advantageous for the manipulative precision and power squeeze grips used during stone tool use and production. There are several reviews of the morphological evidence for manipulative behaviours in human evolution. However, recent palaeontological and archaeological discoveries, as well as advances in methods for analysing morphological remains, have shed new light on the manipulative abilities of early hominins. Thus, palaeoanthropologists have debated the taxonomic attribution and manipulative capabilities of many early fossil hominins for several decades. craniodental material) or stone tool evidence. Furthermore, the morphological evidence for the majority of our evolutionary history has been limited to isolated hand bones that are not directly associated with taxonomically identifying remains (i.e. Thus, researchers are generally forced to focus their interpretation and understanding of the evolution of human manipulative behaviours on fossilized hand anatomy, especially in the earliest stages of human evolution (e.g. However, evidence of the modification and use of organic materials as tools either does not preserve in the fossil record or is not recognizable as tools. Comparative extant primate studies, showing a dominance of using organic plants as tools in New and Old World monkeys and hominoids, suggests that the modification of plants and tool use were behaviours probably present in the last common ancestor of humans and Pan (chimpanzees and bonobos), and potentially evolved multiple times in extinct fossil primates and hominins. ![]() Inferences about manipulative ability and potential tool-related behaviours in the earliest hominins must rely largely on morphological fossil evidence. In particular, recent, relatively complete fossil hominin hand skeletons and archaeological discoveries have added greatly to the growing group of palaeoanthropologists and archaeologists open to the idea that enhanced manual dexterity and tool-related behaviours have been a part of our evolutionary history for much longer than traditionally believed (see also ). However, a growing wealth of palaeontological, archaeological and comparative primate evidence makes clear that Washburn's assertion that pre- Homo ‘ape-men’ were making and using tools still holds true today. In the decades following, tool use and tool making were largely considered to be an ability limited to (and, indeed, used to define) the genus Homo (see for a review). ![]() ![]() Only a few months later the remains of Homo habilis Olduvai Hominid (OH) 7 were discovered and quickly deemed the maker of these stone tools, while Zinjanthropus was considered likely to be the prey instead. Washburn's (see also ) declaration referred to the contemporary discoveries by the Leakey family of the robust australopith skull of ‘ Zinjanthropus boisei’ in association with a living floor of Oldowan stone tools. ‘Now it appears that man-apes-creatures able to run… and with brains no larger than those of apes now living-had already learned to make and to use tools’. ![]()
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