Scientists have long linked the evolution of the human hand—unique for its lengthy opposable thumbs and dexterous fingers—to the rise of stone tools some 2.6 million years ago.
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Early hominins practiced an array of tool-related activities, including hunting, foraging and cooking. But according to a new study from researchers at Chatham University and the University of Kent, not all of these activities were created equal. The team’s findings, newly published in the Journal of Human Evolution, suggest that a specific behavior—smashing animal bones to access their marrow—had an outsized effect on the development of early hand anatomy.
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Bone marrow is a tasty, high-energy food. Early humans who had hands more suited to smashing open bones and acquiring the delicious snack might have been better equipped to survive in the harsh conditions of prehistory, and thus more likely to pass their genes—and dextrous hands—on to the next generation. To test that hypothesis, the team asked 39 volunteers to don a manual pressure sensor system called Pliance and demonstrate a bevy of Pleistocene-era activities.
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[R]esearchers found that the thumb, index and middle fingers always played a role of high importance. Behaviors requiring the most pressure were hammering bones for marrow.…
[T]he newfound emphasis on rich, high caloric-marrow draws attention to the variety of practices that contributed to today’s nimble fingers.Read full, original post: Did the Human Hand Evolve as a Lean Mean Bone-Smashing Machine?
