Chapter 9 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 • Homo erectus was the first hominid to expand into new regions of the Old World. • As a species, H. erectus existed over 1 million years. • The behavioral capacities of H. erectus, along with the morphological changes, help us understand its success as a hominid species.
Homo erectus • In the last few decades, discoveries from East Africa established Homo erectus by 1.8 m.y.a. • Some researchers see anatomical differences between these African discoveries and the Asian discoveries. • They place the African fossils into a species, they call Homo ergaster. • Analyses show that 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 compared to earlier hominids. • 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 • The discovery of the Dmanisi materials began in the early 1990s. • The most informative specimens are four well-preserved crania, with one recently discovered being almost complete. • These remains are the best-preserved hominids of this age found anywhere outside of Africa • They show a mixed pattern characteristics, some quite unexpected.
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.
1. The most obvious feature of Homo erectus that differs from both early Homo and Homo sapiens is _____________ size.
Answer: cranial • The most obvious feature of Homo erectus that differs from both early Homo and Homo sapiens is cranial size.
2. Of the fossil remains at Zhoukoudian, • 40% belonged to individuals under 14 years old. • 20% belonged to individuals 50-60 years old. • nuclear families were clearly represented. • all of these choices
Answer: a • Of the fossil remains at Zhoukoudian, 40% belonged to individuals under 14 years old.
3. Discoveries in Dmanisi in the Republic of Georgia have pushed back the time frame for hominids in Europe. • True • False
Answer: True • Discoveries in Dmanisi in the Republic of Georgia have pushed back the time frame for hominids in Europe.
4. Homo ergaster is the taxonomic name suggested by some scientists for Asian erectus finds. • True • False
Answer: False • Homo ergaster is the taxonomic name suggested by some scientists for African erectus finds.
5. Compared to earlier members of the genus Homo, Homo erectus was • smaller overall. • larger overall. • more or less the same size. • varied.
Answer: b • Compared to earlier members of the genus Homo, Homo erectus was larger overall.