Human evolution: early thumb tool grip advance (Introduction)

by David Turell , Friday, January 29, 2021, 00:45 (1392 days ago) @ David Turell

More interesting thoughts and anew approach to brain and hand development relationships:

https://cosmosmagazine.com/the-body/thumbs-up-and-over/?utm_source=Cosmos+-+Master+Mail...

"Dexterous thumbs – considered a hallmark of being human – were present two million years ago, according to a study published in the journal Current Biology.

"This was around the time that more systematic tool production and complex cultural developments emerged and our large-brained Homo erectus ancestors appeared on the scene, highlighting the pivotal importance of thumb evolution.

“'Increased thumb dexterity [offered] a crucial evolutionary advantage for the gradual development of sophisticated behaviour and culture,” says senior author Katerina Harvati, from Eberhard Karls University of Tübingen, Germany.

“'Importantly, the fact that all later species of Homo maintained, or independently developed, increased levels of dexterity underlines the vital adaptive value of thumb opposition efficiency in human evolution.”

***

"more recent hominins showed greater levels of thumb dexterity similar to those of modern humans, including Neanderthals and Homo sapiens, as well as Homo naledi.

“'It is worth noting that the enigmatic and small-brained species Homo naledi also showed similarly high levels of dexterity,” says Harvati, “despite the fact that its cultural remains are still to be discovered.”

"But “such enhanced manual abilities in this small-brained species suggest a decoupling of the traditionally assumed correlation between brain size and tool-using skills in the fossil record”, the authors write." (my bold)

Comment: The bold is a very interesting take on how advances in human development are related if at all. My view, with God as the designer, decoupling makes sense, as it is up to Him to decide wherever when to create advances in hominin and homo forms.