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Chapter 12. The Earliest Dispersal of the Genus Homo: Homo erectus and Contemporaries. Chapter Outline. A New Kind of Hominid The Morphology of Homo erectus Who Were the Earliest African Immigrants? Historical Overview of Homo erectus Discoveries
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Chapter 12 The Earliest Dispersal of the Genus Homo: Homo erectus and Contemporaries
Chapter Outline • A New Kind of Hominid • The Morphology of Homo erectus • Who Were the Earliest African Immigrants? • Historical Overview of Homo erectus Discoveries • Technological and Population Trends in Homo erectus • Interpretations of Homo erectus: Continuing Uncertainties
Homo erectus • First hominid to expand into new regions of the Old World. • Existed over 1 million years. • The behavioral capacities & morphological changes.
Homo erectus • African discoveries established Homo erectus by 1.8 m.y.a. • Some researchers see anatomical differences: • African fossils as Homo ergaster. • H. erectus/ergaster represents a different grade of evolution than their African predecessors.
Morphology of Homo erectus • Brain size is related to overall body size. • Body sizedramatically increased. • Cranium had a distinctive shape with a thick cranial bone and large brow ridges. • Shovel-shaped incisors suggest an adaptation in hunter-gatherers.
The Dmanisi Hominids • Early 1990s discovery of the Dmanisi. • The most informative specimens are four well-preserved . • Best-preserved hominids of this age outside of Africa • Mixed pattern characteristics.
The Dmanisi Hominids • The Dmanisi crania have some similarities to H. erectus, while some characteristics are different from other hominid finds outside of Africa. • The most complete specimen has a less robust and thinner browridge, a projecting lower face, and a large upper canine. • All three Dmanisi crania have small cranial capacities. • A number of stone tools, similar to early ones from Africa, have been recovered at Dmanisi.
Questions Raised by the Dmansi Discoveries • Was Homo erectus the first hominid to leave Africa—or was it an earlier form of Homo? • Did hominids require a large brain and sophisticated stone tool culture to disperse out of Africa? • Was the large, robust body build of H. erectus a necessary adaptation for the initial occupation of Eurasia?
Discoveries in Java • Six sites in eastern Java have yielded all the H. erectus fossils found on this island. • Dates range from 1.8 m.y.a. to 1.6 m.y.a. • The Ngandong individuals date from 50,000 to 25,000 y.a. • If the Ngandong dates are correct it would make Homo erectus and Homo sapiens contemporaries. • In Java, no artifacts have been found that can be associated with Homo erectus.
Discoveries in Peking • “Dragon bones” used as medicine and aphrodisiacs were ancient bones. • 40 male and female adults and children have been found near Zhoukoudian. • The site was occupied for 250,000 years. • 40% of the bones were from individuals less than 14 years old, 2.6% were from individuals between 50-60 years.
Discoveries in East Africa • Louis Leakey unearthed a fossil skull at Olduvai. • An almost complete skull was discovered in east Turkana. • The most complete H. erectus skeleton ever found was uncovered in west Turkana. • In Ethiopia, an abundance of Acheulian tools have been found as well as a robust mandible dating to 1.3 m.y.a.
East African Homo erectus • East African specimens have thinner cranial bones than those found in Asia. • Some scientists argue that the African and Asian erectus finds should be classified as separate species. • The African and Asian populations are separated by more than one million years.
Technological Trends in Homo erectus • Expansion of the brain enabled H. erectus to develop sophisticated tools: • Biface - stone that was worked on both sides and used to cut, scrape, pound, and dig. • Thousands of Acheulian hand axes have been found with remains of large animals. • Homo erectus is seen as a potential hunter and scavenger.
Small Tools ofthe Acheulian Industry • (a) Side scraper • (b) Point • (c) End scraper • (d) Burin
Trends in Homo erectus • Homo erectus liked to travel. • Stone tools found on the island of Flores, suggest that H. erectus constructed ocean-going vessels. • Homo erectus embraced culture as a strategy of adaptation.