Biomechanics of the human thumb and the evolution of dexterity
A new article has recently been published in Current Biology by Katerina Harvati, Alexandros Karakostis and their team. The article results from a collaboration between different institutions in Tübingen and Europe, namely the Paleoanthropology department in Tübingen, the Hertie Institut für Klinische Hirnforschung (HIH) in Tübingen, the Naturhistorischen Museum Basel und the Medical School of Athens. This research is a great achievement in the field of Paleoanthropology, which received great media attention.
Click here for the article: https://doi.org/10.1016/j.cub.2020.12.041
Systematic tool production and use is one of humanity’s defining characteristics, possibly originating as early as >3 million years ago.1–3 Although heightened manual dexterity is considered to be intrinsically intertwined with tool use and manufacture, and critical for human evolution, its role in the emergence of early culture re- mains unclear. Most previous research on this question exclusively relied on direct morphological compar- isons between early hominin and modern human skeletal elements, assuming that the degree of a species’ dexterity depends on its similarity with the modern human form. Here, we develop a new approach to inves- tigate the efficiency of thumb opposition, a fundamental component of manual dexterity, in several species of fossil hominins. Our work for the first time takes into account soft tissue as well as bone anatomy, integrating virtual modeling of musculus opponens pollicis and its interaction with three-dimensional bone shape form. Results indicate that a fundamental aspect of efficient thumb opposition appeared approximately 2 million years ago, possibly associated with our own genus Homo, and did not characterize Australopithecus, the earliest proposed stone tool maker. This was true also of the late Australopithecus species, Australopithecus sediba, previously found to exhibit human-like thumb proportions. In contrast, later Homo species, including the small-brained Homo naledi, show high levels of thumb opposition dexterity, highlighting the increasing importance of cultural processes and manual dexterity in later human evolution.
Here are the links to the article in the University of Tübingen Press and some news:
Links to TV interviews from Dr. Karakostis:
1. SWR: https://www.swr.de/swraktuell/baden-wuerttemberg/tuebingen/neue-erkenntnisse-ueber-zangengriff-des-menschen-100.html
2. ERT (National Greek television): https://www.ertflix.gr/ert1/syndeseis/09fev2021-syndeseis/ (*at minute 45.20)
Inside Science Magazine: https://www.insidescience.org/news/2-million-year-old-fossils-reveal-whats-ancient-thumbsZurück