Working out how ancient species lived is often difficult , especially when trying to figure out how they sense thing . This is because most sensory organ , like the eye and tongue , are made of soft tissue that do n’t preserve well , forcing scientists to make assumptions from special data . Yet there is one sense – hearing – that can be studied because it is based , in part , on skeletal social structure , albeit very tiny ones . front at the capitulum clappers and auditory canal from two specie of human ancestor from South Africa , researchers have been able toreconstruct their auditory sense ability .
What they found was that while in oecumenical the earlyhominins’hearing was similar to that of chimpanzees , they could try a slimly wider chain of mountains of absolute frequency , which is more standardized to advanced humans . These modification in how they could hear things , moving away from chimps and closer to humans , could have bear on the mode they communicated and in the end put them one step closer to the development of terminology . Interestingly , it also seems that the ancient hominins had an increased sensitiveness to higher frequency , perhaps related to the environment they were living in , say the researcher .
“ We know that the audience formula , or audiograms , in chimpanzees and humans are clear-cut because their hearing ability have been measured in the science laboratory in living subjects , ” explains Rolf Quam , carbon monoxide gas - generator of the work published inScience Advances , in astatement . “ So we were interested in finding out when this human - like hearing design first emerged during our evolutionary history . ”
A sidelong sight of the Paranthropus robustus skull SK 46 that was found at the Swartkrans site in South Africa . The above range of a function render the 3D virtual reconstruction of the ear and the auditory modality results for the early hominins . quotation : Rolf Quam
The cogitation comes on the back of the discoverya few years agoof the sodding solidifying of lilliputian mediate - auricle bones from two species of ancient hominins , Australopithecus africanusandParanthropus robustus , which were living in South Africa between 3.3 and 2.1 million yr ago . Using these and CT scans of the fossil skulls , the team was able to construct the inner material body of the ear . From this , they were able-bodied to revivify the audiogram for each species .
It appears the ancient hominins had a large sensitiveness to higher frequency , from around 1.0 - 3.0 kHz , when compare to either Pan troglodytes or modern human . This , the researchers suggest , could be an adjustment to experience on the savannah , where wakeless waves do n’t travel as far as in the forest canopy and where animals have to rely on short - ambit communication .
This could have implications for the development of spoken communication within the human lineage , although Quam in no room thinks that these other mintage were at that degree yet . “ They certainly could communicate vocally . All hierarch do , but we ’re not saying they had fully developed human speech communication , which implies a symbolic content , ” hesays .
Others , though , havepreviously questionedthe truth of using the middle - ear bones to count on hearing power , claiming that it ’s really the embodiment and size of the outer spike that has a great influence on hearing ability in prelate . The research worker of this new study are , however , confident that their work is exact , and could ply valuable sixth sense into when voice communication potentially developed .
Main image : Tim Evanson / Flickr CC BY - SA 2.0
