일반명 : 호모 에르가스테르(일하는사람)
학 명 : Homo ergaster (KNM-ER 3733)
시 대 : 1.75 MYA.
발견지역 : Koobi Fora, Kenya
발견시기 : 1975
발견자 : B. Ngeneo
1.75 MYA. The Homo ergaster Skull KNM-ER 3733 with dentition was discovered by B. Ngeneo in 1975 in Koobi Fora,
Written by C. David Kreger
Introduction
Homo ergaster is one of the more problematic of somewhat accepted species designations currently tossed around in anthropological literature. Each individual researcher that sees ergaster as a valid taxon sees different specimens as belonging or not belonging to the taxon. Many researchers deny any validity to the species at all. On the whole though, most researchers see too little difference between ergaster and erectus to form the basis of a species of the former, separated from the latter. As a general rule of thumb, one can consider most attributed ergaster specimens to be early erectus geographically confined to
The taxon ergaster was first described in 1975 by C. Groves and V. Mazak. The specimen attributed as the type specimen was ER 992, an isolated mandible. Since then, other specimens have been attributed by various authors to ergaster, with most researchers placing the same fossils in erectus. Those who see it as a valid taxon tend to see it as more closely resembling modern H. sapiens than does H. erectus. They tend to see ergaster as a direct ancestor of modern humans with erectus being an evolutionary dead-end. Many Out of Africa supporters use this taxon as evidence that Asian and European specimens did not contribute genetically to the modern human genome, but this claim is very weak.
Diagnostic Features
The type specimen for ergaster is KNM-ER 992.
One of the most spectacular and important paleoanthropological finds in recent years was the Nariokotome Boy (
Several researchers have tried to define the difference between ergaster and erectus, P. Andrews and B. Wood among the more prominent. P. Andrews defined seven autopomorphies that were characteristic of erectus, but which ergaster supposedly lacked. However, G. Bräuer have shown that these are not autopomorphies. For example, some erectus do not possess these features, while some ergaster and some habilis do. Also, some of these autopomorphies are not independent traits, and should not be considered separately (e.g., frontal keel and parietal keel). B. Wood lists seven traits that link ergaster with H. sapiens, and that distinguish ergaster from erectus:
However, these synapomorphies have been convincingly challenged by showing them to be present in erectus populations from
Conclusions
In short, H. ergaster does not show significant promise of lasting as a separate taxon due to several factors. It has not been shown to be significantly different from erectus to require the designation of a new hominid species, and it has not been shown to be closer to modern humans morphologically as has been claimed by some. At this time, ergaster basically means early H. erectus from
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