Hem > Antropologi > Neandertalarna arbetade med läder

Neandertalarna arbetade med läder

juli 20, 2012

En ny studie visar att neandertalarnas kraftiga högerarm inte är ett resultat av att stöta spjut i byten utan är ett resultat av att arbeta med skrapor. Forskarna vid Cambridges universitet lät utsätta moderna människor för olika typer av arbeten och gjorde mätningar av deras muskler. De jämförde mellan fyra olika sätt att stöta spjut och tre olika sätt att skrapa.

De fann att stöt med spjut ledde till att muskelaktiviteten på vänster sida av kroppen var högre än på den högra. Skrapning gav upphov till mer muskelaktivitet på den högra sidan av kroppen. Detta stämmer väl med neandertalarnas kroppsbyggnad.

Därav dras slutsatsen att neandertalarnas kraftiga högersida inte har sin uppkomst i stötning av spjut utan i skrapning av exempelvis läder.

Science Daily

Abstrakt:
Unique compared with recent and prehistoric Homo sapiens, Neandertal humeri are characterised by a pronounced right-dominant bilateral strength asymmetry and an anteroposteriorly strengthened diaphyseal shape. Remodeling in response to asymmetric forces imposed during regular underhanded spear thrusting is the most influential explanatory hypothesis. The core tenet of the “Spear Thrusting Hypothesis”, that underhand thrusting requires greater muscle activity on the right side of the body compared to the left, remains untested. It is unclear whether alternative subsistence behaviours, such as hide processing, might better explain this morphology. To test this, electromyography was used to measure muscle activity at the primary movers of the humerus (pectoralis major (PM), anterior (AD) and posterior deltoid (PD)) during three distinct spear-thrusting tasks and four separate scraping tasks. Contrary to predictions, maximum muscle activity (MAX) and total muscle activity (TOT) were significantly higher (all values, p<.05) at the left (non-dominant) AD, PD and PM compared to the right side of the body during spear thrusting tasks. Thus, the muscle activity required during underhanded spearing tasks does not lend itself to explaining the pronounced right dominant strength asymmetry found in Neandertal humeri. In contrast, during the performance of all three unimanual scraping tasks, right side MAX and TOT were significantly greater at the AD (all values, p<.01) and PM (all values, p<.02) compared to the left. The consistency of the results provides evidence that scraping activities, such as hide preparation, may be a key behaviour in determining the unusual pattern of Neandertal arm morphology. Overall, these results yield important insight into the Neandertal behavioural repertoire that aided survival throughout Pleistocene Eurasia.

PloS ONE

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Kategorier:Antropologi
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