The clavicle of anunknown hominidthat be in East Africa around 1.8 million years ago is remarkably similar in distance and curvature to that of a barrel - chested mod man . discover in Tanzania in 2005 , the ancient fossil provides grounds that our ancient root may have been as broad as we are , despite differences in superlative and overall size of it .
Also known as theclavicle , the clavicle cater intriguing insight into the biomechanical forces that playact on the forelimb during different types of travel . As such , analyses of ancient hominid clavicles have been used to draw decision regarding climbing ability , manual sleight , and throwing king , among other thing .
Given the considerable differences between humans and aper , one would course expect the oldest hominid collarbones to differ substantially from those of modern humans . To try out this possibility , the author of a field – which has been posted as a preprint and has not yet been indorse by match review article – compared the ancient osseous tissue from Tanzania with the clavicles of modern mankind , gorillas , chimpanzees , and baboons , as well as several ancient species including Neanderthals , Homo erectusand the iconicAustralopithecus afarensis .
Despite ethical concerns , the research worker obtained modern human clavicles from the remains of multitude who died in the Cleveland area more than 100 yr ago and “ whose bodies were unclaimed from hospital and morgues . ”
“ These people therefore disproportionately represent miserable - income grouping and , given the measure of aesculapian ethics at the time , most likely did not tally todonate their remainsto science , ” write the writer apologetically .
overcome their moral hesitation , the researchers distinguish that the overall length of the ancient collarbone was similar to that of a large human male person , while the bone ’s curve was also “ relatively human - like congenator to its length . ” They therefore conclude that the fossil “ deduce from an individual with a shoulder joint width similar to a great male today . ”
Despite the fact thatarchaeologicalrecords indicate the presence of at least two distinguishable hominid species in Tanzania around 1.8 million days ago , the study generator were unable to confirm which species the collarbone might have belonged to . However , given the striking similarity between the ancient clavicle and New clavicle , the research worker theorize that “ the evolutionary and biomechanical military force play on the arms and berm of 1.8 - million - yr - old hominids are not entirely dissimilar to those acting on mod humans today . ”
“ This finding indicates that there has been little morphologic change in the hominid clavicle in the last ~2 million year , ” they publish . “ It also suggest that berm breadth ( though not necessarily body size of it ) may have been similar to modern human beings as far back as 1.8 [ million year ago ] . ”
The preprint has been mail toBioRxiv .
