User:Cgarc070/Australopithecus garhi
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Tool Use
[edit]Au. garhi butchered animals about 2.5Ma.[1] Through recent cut-mark data, researchers found that during this time was when early hominin started to manufacture and use tools. Au. garhi was one of the earliest hominids to utilize Oldowan tool technology.[2] Early stone tools were utilized by Au. garhi to slice meat from dead animals and smash its bones to get to the bone marrow inside.[2]
Diet
[edit]Although this early hominin had a cranial capacity of only 450 cc, changes to Au. garhi's diet led to rapid growth of its brain which resembled the human brain.[1] A diet rich in protein, which is contained in meat, allowed for this rapid change. Additionally, Au. garhi's protruding jaw flattened out over time due to the change in eating habits.[1]
Anatomy
[edit]Au. garhi had a well mix of robust and humanlike features that often led to researchers being confused on the possible lineage to the genus Homo. It is believed that this mixture of features was cause by climate change.[1] Additionally, in 1996 it was discovered that Au. garhi’s had a relatively long femur like humans, but also long arms like those of apes and early australopithecines.[1] Anthropologist Owen Lovejoy who teaches at Kent State University in Ohio states that the reason of this morphology is that “the fossils show that human proportions evolved in steps, with the legs lengthening before the forearms shortened.”[1]
Dentition
[edit]Paleoanthropologist Fred Grine found that Au. garhi showed a weak connection between its dentition and the dentition of the Homo genus.[1] It resembled early hominin of the genus Homo but was found to have even larger molars than Au. robustus.[1] Au. Garhi’s second molar is 17.7 millimeters across.[1] Although classified as an Australopithecus, Au. garhi differs from Au. afarensis “by its absolutely larger postcanine dentition and an upper third premolar morphology with reduced mesiobuccal enamel line projection and less occlusal asymmetry.” [3]Australopithecus garhi also does not display the dental, cranial, and facial features of those common between A. aethiopicus, A. robustus, and A. boisei.[3]
Taxonomy
[edit]Due to the differences between Au. garhi and other Australopithecines, there is a controversial taxonomic discussion on whether or not Au. garhi should be categorized under the genus Homo or if it should be kept under Australopithecines.[4] Its small cranial capacity resembles Australopithecines such as boisei and afarensis, but its meat eating habits as well as its bipedal locomotion signal it to be more of a hominin from the genus Homo. However, the hypothesis of the specimen BOU-VP-12/130, or Au. garhi, being ancestral to the genus Homo has been tested through cladistical analysis and has proven that Au. garhi is not a direct ancestor of the Homo- genus until now.[4]
References
[edit]- ^ a b c d e f g h i Culotta, Elizabeth (1999). "A New Human Ancestor?". Science. 284 (5414): 572–573. ISSN 0036-8075.
- ^ a b Semaw, Sileshi (2000-12). "The World's Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago". Journal of Archaeological Science. 27 (12): 1197–1214. doi:10.1006/jasc.1999.0592.
{{cite journal}}: Check date values in:|date=(help) - ^ a b Asfaw, Berhane; White, Tim; Lovejoy, Owen; Latimer, Bruce; Simpson, Scott; Suwa, Gen (1999-04-23). "Australopithecus garhi: A New Species of Early Hominid from Ethiopia". Science. 284 (5414): 629–635. doi:10.1126/science.284.5414.629. ISSN 0036-8075. PMID 10213683.
- ^ a b Strait, David S.; Grine, Frederick E. (2019-05-31). "The systematics of Australopithecus garhi". Ludus Vitalis. 9 (15): 109–135. ISSN 1133-5165.