Eating bone marrow played a key role in the evolution of the human hand

July 11, 2018, University of Kent
Student using stone tool. Credit: Erin Marie Williams-Hatala

The strength required to access the high calorie content of bone marrow may have played a key role in the evolution of the human hand and explain why primates hands are not like ours, research at the University of Kent has found.

In an article in The Journal of Human Evolution, a team lead by Professor Tracy Kivell of Kent's School of Anthropology and Conservation concludes that although stone making has always been considered a key influence on the evolution of the human , accessing generally has not.

It is widely accepted that the unique dexterity of the human hand evolved, at least in part, in response to stone tool use during our evolutionary history.

Archaeological evidence suggests that early hominins participated in a variety of tool-related activities, such as nut-cracking, cutting flesh, smashing bone to access marrow, as well as making . However, it is unlikely that all these behaviours equally influenced modern human hand anatomy.

To understand the impact these different actions may have had on the evolution of human hands, researchers measured the force experienced by the hand of 39 individuals during different stone tool behaviours—nut-cracking, marrow acquisition with a hammerstone, flake production with a hammerstone, and handaxe and stone tool (i.e. a flake) - to see which digits were most important for manipulating the tool.

They found that the pressures varied across the different behaviours, with nut-cracking generally requiring the lowest pressure while making the flake and accessing marrow required the greatest pressures. Across all of the different behaviours, the thumb, index finger and middle finger were always most important.

Professor Kivell says this suggests that nut-cracking force may not be high enough to elicit changes in the formation of the human hand, which may be why other primates are adept nut-crackers without having a human-like hand.

In contrast, making stone flakes and accessing marrow may have been key influences on our hand anatomy due to the high stress they cause on our hands. The researchers concluded that eating marrow, given its additional benefit of high calorific value, may have also played a key role in evolution of human dexterity.

The manual pressures of tool behaviors and their implications for the of the human hand by Erin Marie Williams-Hatala, Kevin G. Hatala, McKenzie Gordon and Margaret Kasper, all Chatham University, Pittsburgh, USA and Alastair Key and Tracy Kivell, University of Kent is published in the Journal of Human Evolution.

Explore further: Non-dominant hand vital to the evolution of the thumb

More information: Erin Marie Williams-Hatala et al, The manual pressures of stone tool behaviors and their implications for the evolution of the human hand, Journal of Human Evolution (2018). DOI: 10.1016/j.jhevol.2018.02.008

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6 comments

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Benni
2.8 / 5 (9) Jul 11, 2018
.....so did eating apples..

Anthropology, what a worthless quest of make believe.
torbjorn_b_g_larsson
4.3 / 5 (6) Jul 11, 2018
.....so did eating apples..

Anthropology, what a worthless quest of make believe.


Oy, Said after an exciting article makes such a claim ... well ... worthless (and wrong to boot).
GaryB
2.5 / 5 (2) Jul 12, 2018
Making stone tools needs the most force, and in one of the world's oldest sayings: (s)"he who has the stone has the marrow."

I kind of think if you can make a better weapon, you can get and defend a better mate and that would probably not only kill off the stoner duds, but simultaneously pop out stoned kids. That makes more sense than marrow.

Sheesh, these guys run out of topics to publish on?
Ojorf
4 / 5 (4) Jul 12, 2018
.....so did eating apples..

Anthropology, what a worthless quest of make believe.


How so Benni? You seem to have misunderstood the article.
It is about the evolution of the modern human hand and why it differs from those of our closest living relatives and ancestors..It examines the evolutionary pressures that might have influenced it's unique anatomical structure.
Since primates have been eating fruit since way, way before the evolution of an anatomically modern hand (and still do) , plucking apples could not have resulted in the dexterous hand we ended up with. Tool use and specifically cracking thick bones for marrow might have.
Is that simple enough for you?

rrwillsj
3 / 5 (2) Jul 12, 2018
Sooo, if I understand the whiny whinging wankers correctly? Their complaint is that scientists are researching complex issues that wrankle the wrinkly-butts of the whimpering whiners?

Do any of you sorry lot have the qualifications to direct an anthropological research project?

Or are you just wallowing with religious zeal in your mudhole seeking assurance that you are not the product of lengthy evolution?

But rather, altogether you are a stuporous congregation of rejects. The bungled byblows of Stupid Design by drunken deities. To incompetent to improve your decidedly inferior lineage of failed evolution?
TheGhostofOtto1923
not rated yet Jul 14, 2018
whiny whinging wankers bungled byblows of Stupid Design by drunken deities. To incompetent to improve your decidedly inferior lineage of failed evolution?
"psychopaths seem to have trouble monitoring their own speech. What is more, they often put things together in strange ways..."

"...their frequent use of contradictory and logically inconsistent statements that usually escape detection. Recent research on the language of psychopaths provides us with some important clues to this puzzle, as well as to the uncanny ability psychopaths have to move words - and people- around so easily."

"...the language of the psychopath is two-dimensional. They are, as someone once said, as "deep as a thimble." An analogy is given of the psychopath as a color blind person who has learned how to function in the world of color by special strategies."
https://www.cassi...path.htm

-outed again.

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