The Homo ergaster also known as the "African Homo erectus" is an extinct chronospecies of the Homo henus that lived in eastern and southern Africa during the early Pleistocene between 1.8 million and 1.3 million years ago.
Scientists are still debating the classification, lineage and descendants of the Homo ergaster but it is widely accepted that it is a direct ancestor of ancient hominids such as the Asian Homo erectus, Homo heidelbergensis, Homo sapiens, and Homo neanderthalensis.
Classification
Some paleoanthropologists refer to H. ergaster as the simple African species of Homo erectus. This has led to the use of the term "Homo erectus sensu stricto" for Asian Homo erectus, and "Homo erectus sensu lato" for larger species forming both early African populations (Homo ergaster)and Asian populations. Some scientists have suggested that the Homo ergaster was the direct African ancestor of the Homo erectus suggesting that the Homo ergaster left Africa and migrated to Asia that breed a unique species.
Evolution
H. ergaster is believed to have evolved from its ancestor Homo around 1.9 and 1.8 million years ago. The H. ergaster clan who left Africa and traveled to Asia separated from the ergaster line and became Homo erectus. Both Homo antecessor and Homo heidelbergensis are believed to be evolved from H. ergaster. H. ergaster remained stable for ca. 500,000 in Africa before disappearing from the fossil record some 1.4 million years ago.
Characteristics The Homo ergaster used a lot more sophisticated and sophisticated stone tools than its Homo ancestor. It developed the Oldowan name and developed the first Acheulean axes Although the use of Acheulean tools began in ca. 1.6 million years ago, the H. erectus line was isolated about 200,000 years before the general introduction of Acheulean technology and so H. ergaster Asian descendants did not use Acheulean technology.
Sex formation in H. ergaster was significantly reduced from its australopithecine ancestors about 20% but was still significantly higher than in modern humans. This reduced dimorphism is supposed to be a sign of reduced competition for sex between men. H.ergasters are like modern humans in organization and socialization like any of the earlier species. H.ergaster is believed to be the first hominin to control fire or create fire but scientists are still debating it. It is believed that Homo erectus controls the fire as well as other hominins that share common ancestry with H.ergaster.
According to the BBC series Walking With Cavemen, the Homo ergaster was probably the first hominid to use "recognizable a human voice" although its symbolic cognition was probably limited compared to modern humans. H.ergaster is believed to be limited in its ability to regulate breathing and create complex sounds. It is based on the cervical vertebrae of the Turkana boy which is much narrower than that of the ancients. Cervical vertebrae findings in Dmanisi, Georgia some 300,000 years ago in the Turkana boy were within normal range.