This process is at odds with the usual evolutionary story of humans - who use their longer thumbs to build tools to conduct research, write about their findings and grasp and manipulate fine objects like an iPhone. “Humans are very good at using their hands to manipulate things and little hand evolution was necessary to allow this” because the likely starting point was “already pretty good,” he said. Almécija’s analysis, however, suggests the most likely scenario is one in which humans changed little, with our fingers slightly shorter and thumbs slightly longer, than our ancestors, while chimps have had elongated digits to help them move around in trees. This process would have started about three million years ago, when humans produced stone tools in a systematic way. “The generally accepted hypothesis is that our hand proportions went through dramatic changes, starting from a chimp-like hand with long digits and relatively short thumb by means of selective pressure,” Almécija explained. He published this research recently in the journal Nature Communications. He discovered that human hands haven’t changed that dramatically over the last several million years, while those of chimpanzees have shown considerably more variation, with the length of their fingers getting longer relative to their thumbs. In looking at hand bones, Almécija, working with Jeroen Smaers and William Jungers at Stony Brook, analyzed the length of thumbs compared with fingers. His findings and possible conclusions have, once again, challenged some conventional wisdom. as an assistant professor in the Department of Anthropology, recently compared the hands of humans with chimps and apes. Almécija, who left his post as research instructor at Stony Brook University this summer and joined George Washington University in Washington D.C. Sergio Almécija ruffled feathers in 2013 when he looked at the femur bone of an ape that lived six million years ago and suggested that this leg bone might have been like that of a fossil ape, which upset the usual human evolution story.
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