The monkey has hands-and even feet-very similar to human hands (see illustration). Chimpanzee hands are specialized for arboreal life and confuse the picture, creating what the authors call “the riddle of man’s ancestry.” 2 The Old World monkey is thought to have diverged from the ape-ancestral line before the supposed human-chimp split. In order to get a handle on the evolutionary history of the human hand, the team chose to use an Old World monkey-a macaque-rather than a chimpanzee. Contrary to the ‘hand-in-glove’ notion outlined above, our results suggest that adaptations underlying tool use evolved independently of those required for human bipedality.
#Chimpanzee hand grips manual#
In this study, we sought to shed new light on the origins of manual dexterity and bipedalism by mapping the neural representations in the brain of the fingers and toes of living people and monkeys. Either way, it is commonly thought that one led to the other. Neurobiologist Atsushi Iriki, anthropologist Gen Suwa, and colleagues write: People have long speculated whether the evolution of bipedalism in early hominins triggered tool use (by freeing their hands) or whether the necessity of making and using tools encouraged the shift to upright gait. In answer to the question of which came first-better hands or better feet-the University of Tokyo team says, “Neither!” Which Came First?
#Chimpanzee hand grips free#
But how could coming down from the trees and walking on two legs provide the evolutionary incentive for hominid brains to grow? Did hands finally free to use tools promote hominid brain evolution or did the necessity of using tools make bipedal locomotion the only way to go further up the evolutionary ladder?Ī study published this month in Philosophical Transactions of the Royal Society B reports that brain-mapping data on monkeys and humans resolves this debate. It was generally easier to claim that small-brained extinct fossilized apes were bipedal than that they had big brains, so the bipedal position won out. Once upon a time, the proponents of human evolution debated about which came first-big brains or bipedal locomotion. Science Daily: “ What Evolved First, a Dexterous Hand or an Agile Foot?”.
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