Ancient hominids had hands similar to humans, indicating earlier tool use, study finds

An analysis by Eberhard Karls University in Tübingen, Germany, of the manual abilities of early hominids reveals that some species of Australopithecines exhibited hand use similar to that of modern humans.

By demonstrating that some australopithecine species possessed hand analyses conducive to tool use, the study suggests that tool use may have begun much earlier than previously documented.

The comparative study entitled “Human manual activities in australopithecines”, published in the Journal of Human Evolutionanalyzed the muscle attachment sites on the hands of three species of Australopithecus: A. afarensis, A. africanus and A. sediba. Comparisons have been made using the hands of modern humans, Neanderthals, gorillas, chimpanzees and orangutans to compare the hand use patterns of humans and apes.

According to the study, muscle attachment sites are critical to understanding functional hand use through biomechanical loading. The method allows for a deeper reconstruction of habitual activities and manual behaviors, allowing us to see the effects of sustained tool use on hand biomechanics and, from there, to learn much about how whose tool could have been used.

The study used three-dimensional models of the hand bones to study the biomechanics in detail. Areas of muscle attachment were identified based on differences in bone surface elevation, staining (if available), and surface complexity. The identified areas were carefully demarcated to separate the muscle attachment sites from the rest of the bone.

The results indicate that A. sediba and A. afarensis possessed muscle attachment patterns suggesting that they possessed the anatomical basis necessary for manipulative activities similar to those of humans. This implies that these species engaged in tasks such as power grasping and in-hand object manipulation essential to tool use.

A. africanus exhibited a combination of attachment characteristics, indicating both human and ape hand use. This mosaic pattern suggests versatility in manual behaviors, potentially influenced by tool-related activities.

“The frequent activation of the muscles needed to perform human-like grasping and manipulation in these early hominids supports the idea that human-like use of the hand arose before, and likely influenced, adaptations evolution for higher manual dexterity in later hominids,” the researchers say. in their newspaper.

The oldest stone tools ever discovered date from around 3.3 million years ago, but they contain no fossil remains to confirm who used them. Even older evidence (about 3.4 million years ago) of cut marks on the bones of large mammals shows that tools were used to melt down meat.

Early tool makers probably relied heavily on bone or wooden tools, making it extremely unlikely to find traces of their existence. Yet the current study could tell us more than the artifacts alone.

We may never know the extent of the tools in the australopithecus toolbox, but if you raise your hand you’ll see evidence of their use.

Overview of the three hominids studied

Australopithecus afarensis lived around 3.9 to 3 million years ago and was primarily found in East Africa. They were able to walk on two legs while retaining some typical tree climbing characteristics. The braincase was smaller with a prominent brow bone and facial features more ape-like than the others. The group is well represented by “Lucy”, one of A’s skeletons. afarensis the most complete and best preserved ever discovered and perhaps the most famous anthropological celebrity in the world.

Australopithecus africanus lived around 3.3 to 2 million years ago and was discovered mainly in South Africa. Also bipedal and adapted for both upright walking and climbing, hominids had arms longer than legs compared to later Homo species. The puzzle was bigger than A’s. afarensis, with a more rounded skull. They had smaller molars and larger canines, indicating a varied diet of hard vegetation and softer foods. They are one of the most successful hominids in terms of longevity in a persistent form (four times longer than current modern humans).

Australopithecus sediba lived approximately 2 to 1.8 million years ago and was discovered in the Malapa region of South Africa. They were also bipedal and retained their climbing ability. They had a slightly larger braincase than earlier australopithecine species.

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