Evolution and humans: Neanderthal hand usage (Evolution)

by David Turell @, Wednesday, September 26, 2018, 20:25 (333 days ago) @ David Turell

It turns out the muscle attachments indicate fine control:

https://www.newscientist.com/article/2180724-neanderthals-had-dexterous-hands-that-coul...

"Neanderthals could hold objects between finger and thumb, just like we would hold a pen, because their hands were more nimble than anyone thought.

"The finding helps explain the many skilful tasks Neanderthals have been shown to have performed, like making tools, painting on cave walls, carving patterns into bird bones and threading sea shells onto string to make jewellery. These activities were hard to explain if they were clumsy.

"Neanderthal hand bones were much chunkier than ours, implying a lack of fine control. Previous studies of the bones mostly suggested Neanderthals could not perform a “precision grip” with finger and thumb, and instead had to use a “power grip” using their whole fist – the way small children sometimes hold crayons.

"To find out how they used their hands, Katerina Harvati of the University of Tübingen in Germany and her colleagues studied “entheses”: the points on the bones where muscles were attached.

"Each enthesis is a raised area of bone. “To the touch it feels like a smooth bump on the surface of the bone,” says Harvati. Her team has developed a 3D scanning method that accurately measures their surface area. A precision grip uses a different set of muscles to a power grip, and those muscles that get used more develop larger entheses. Harvati’s team previously showed this by studying modern humans who had worked different jobs.

"The team examined the hand entheses of six Neanderthals and six early modern humans. The Neanderthals spent most of their time using precision grips, while the early modern humans used both precision and power grips.

“'Our study reconciles the archaeological with the anatomical fossil evidence,” says Harvati.

“'It was previously proposed that Neanderthals relied on force for their manual activities,” but this perception “was at odds with mounting archaeological evidence for sophisticated cultural behaviour of Neanderthals”.

"The fact the Neanderthals only used precision grips “suggests that the nature of their activities did not substantially differ across individuals”, says Harvati. While each Neanderthal probably performed a mix of tasks, these tasks were likely similar. In contrast, the modern humans seemed to have had a division of labour. The sample “comprised some individuals with habitual precision grips, and some with habitual power grips.'”

Comment: Gradually reasonable studies are showing that Neanderthals were very similar to us.


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