Violence may have played a larger role in our evolution than we thought . By studying the faces ofaustralopiths , our first full bipedal ancestors , researchers show how the strongest parts of their skull were place that were most potential to be punched . Those features may have minimized injury during hand - to - hired hand fights .
The earliest members of the genusAustralopithecuslived around 4 million years ago . They had clearly rich faces , and for the past several tenner , researchers get by that these feature were functionally related to their dieting of hard objects , like nut or tough plants .
On the other hand , University of Utah ’s David CarrierandMichael Morganargue that the hand proportions that take into account us to clinch our hand into a clenched fist evolve as a resolution of selection to make the hand a weapon . " The australopiths were characterized by a suite of trait that may have amend fight ability,“Carrier says , " in effect turning the ticklish musculoskeletal arrangement of the hand into a nine effective for take up . " And as the chief mark , the brain would have undergo development , making it more robust with protective buttressing .
To find evidence for their " protective buttress hypothesis , " the duo reviewed lit on theme rank from the hominin fossil record to modern assault hurt . To identify primary object of interpersonal violence , they attend at injuries affirm during hand - to - handwriting fighting in untrained New humans : The majority were inflicted to the face . Then they compared skulls and reconstructive memory of gorillas ( pictured above ) and chimpanzees , Australopithecus afarensis , Paranthopus boisei , Homo erectus , andHomo sapiens(pictured below ) .
" What we find was that the bones that have the high rates of faulting in fight are the same component of the skull that display the greatest increase in robusticity during the phylogeny of basal hominins , " Carrier explains in anews release . These features – which include bombastic , muscular jaw and more robust cheekbones and eye socket – appear in the fossil platter at approximately the same time our first bipedal ancestors develop the right hired hand proportions for forming a clenched fist . Taken together , their determination advise that many of the facial feature that characterise early hominins evolved to protect the face from fracturing when strike .
Their guess might explain why our species exhibits judge sexual dimorphism in the metier and power of the jaw and cervix . The pearl with the great increase in robusticity " are also the portion of the skull that show the greatest difference between male and females in both australopiths and humans,“Carrier say . " In other words , male and female faces are different because the parts of the skull that break in fights are bigger in males . "
Theworkwas published inBiological Reviewsthis hebdomad .
[ ViaUniversity of Utah ]
Images : David Carrier ( top ) , reconstructions were append by Skulls outright ( middle )
