AAAS—Muscle attachment scars on Neanderthal hands show similarities to the hands of lifelong precision workers, a new study reports. This finding challenges the common belief that Neanderthals relied primarily on force, rather than precision, in their daily activities. The manual activities of Neanderthals are particularly important, as they provide insights into the evolution of tool making and use. Despite work hinting that Neanderthals were anatomically able to perform precision grips using their thumb and index finger like modern humans, there has been no clear evidence that Neanderthals habitually used precise hand movements. New archaeological research on Neanderthal tools, however, such as on bone tools for hide processing, has shown proof of Neanderthal activities that would require fairly high levels of precision; this has resurfaced the question of whether Neanderthals precisely grasped in their daily activities. Attempting to find an answer, Fotios Alexandros Karakostis et al. first used a new 3-D method to analyze hand entheseal surfaces (muscle attachment scars) of modern-day power gripping laborers like construction workers, as compared to modern-day workers, like tailors and artists, in lower-intensity jobs. They identified patterns of entheses indicating significant muscle use relating to power versus precision grips, which allowed them to provide a reliable way to reconstruct habitual physical activities in the past. They then applied this approach to fossil samples of Neanderthals and early modern humans from the Late Middle to Late Pleistocene. The fossils were from locations in Europe, Western Asia and North Africa. Both groups, the Neanderthals and early modern humans, were represented by a total of six individuals each whose entheses were preserved. Neanderthals consistently exhibited characteristics of high systematic precision grasping, the authors say. Contrarily, early modern humans showed signs of both precision and power grasping.
Article Source: AAAS Science Advances news release. Science Advances is published by AAAS, the nonprofit science society.
Cover Image, Top Left: Neanderthal profile recreation. Arturo Balseiro