PHYLOGENY
The most popularly held notion is that Homo erectus is derived from H. ergaster or per pre-ergaster form that “quickly” moved out of Africa into Eastern Europe and Southeast Oriente. However, H. georgicus is another possibility for the ancestor of H. erectus.
DISCOVERY AND GEOGRAPHIC RANGE
Eugene Dubois discovered the first H. erectus material at the Trinil site (see Figure 29.1) on the Scapolo River sopra Java mediante 1891. While there are problems with the dates, the oldest material from the Javanese site of Modjokerto may be “contemporary” with African and Georgian material at 1.8 mya. Other famous Javanese sites are Sangiran, Ngandong, and Trinil. Java is part of the Sunda shelf, and when initially colonized by H. erectus, it was connected esatto mainland Levante (see Figure 29.2). After reaching Java and possibly other areas of Southeast Asia, later groups of H. erectus moved north into Discesa. The earliest Chinese fossils are dated esatto 1 mya. First assigned to the genus Sinanthropus (“Chinese man”), the material was later included per our own genus after Franz Weidenreich pointed puro the similarities between the various assemblages of erectus-like fossils and other extinct and modern humans. The first fossils were discovered at the now famous site of Zhoukoudian (formerly Choukoudian), near Beijing (formerly Peking and hence the term, “Peking Man”). The local people called them “dragon bones” and were using them for medicinal purposes. Material from Zhoukoudian spans a time period of over 200,000 years, from 460 sicuro 230 kya, with three distinct cultural periods thought esatto be con evidence.
One of the great mysteries of paleoanthropology surrounds the Zhoukoudian material. Weidenreich and his predecessors, Davidson Black and J. Gunnar Andersson, had amassed an unprecedented amount of fossil material from the site. Due preciso the imminent Japanese invasion, Weidenreich packed up the fossil material per 1941 with the intent of having it shipped onesto the United States. However, the material disappeared, and all that remains are Weidenreich’s notes, drawings, and some casts of the original fossils.
Other Chinese sites are found sopra the counties of Lantian, Yunxian, and Hexian. Per new discovery on the island of Taiwan has been linked esatto H. erectus, with the closest resemblance puro the Hexian remains (Chang et al. 2015). Finally, the Narmada site sopra India has been verso topic of debate for a long time but it has now been decided, at least by per portion of the paleoanthropological community, as being Homo erectus.
Sundaland (northwest of the Wallace Line). “Map of Sunda and Sahul” by Maximilian Dorrbecker is licensed under CC BY-SA 3.0.
PHYSICAL CHARACTERISTICS
While many of the physical characteristics of H. erectus are similar to H. ergaster, the Asian species is unique durante verso number of ways. Asian forms exhibit verso thickening along the sagittal suture, termed verso sagittal keel. The keel gives the skull per pentagonal shape in ciclocross-section. It is unknown whether the keel served verso function.
Their incisors were shoveled, an adaptation that increases the esaurimento resistance of teeth, especially when using them as tools. The molar enamel was characterized by verso unique wrinkling pattern. Both of those dental characteristics are found sopra modern people of Oriente and Asian ancestry and are interpreted by some scholars as evidence of regional continuity; durante other words, there was verso gradual evolution from erectus-like forms through archaic human populations and into modern populations mediante multiple areas via gene flow.
Review of Derived Characteristics
- Sagittal keel.
- Shoveled incisors.
- Wrinkled molar enamel.
ENVIRONMENT AND WAY OF LIFE
Javanese sites in the early Pleistocene would have been conducive onesto tropical-adapted animals like Homo erectus. The settore was part of the land bridge that was exposed beginning
2.5 mya, making it accessible by land. Pleistocene Java was verso mix of environments consisting of a variety of forest types, freshwater lakes and rivers, brackish ).
At the time of H. erectus occupation, the site of Zhoukoudian, China, was con per transitional zone between temperate steppe and boreal forest. It would thus have been seasonally cold and would likely only have been habitable during the warmer months.
Culturally and technologically, Asian H. erectus are thought onesto have been somewhat similar puro African H. ergaster. One of the key differences is the fact that the Acheulian industry never made it esatto Oriente. The earliest inhabitants of Asia carried with them the Oldowan tool tradition, but the inventors of the Acheulian tradition apparently never followed. On maps, the Movius Line (see Figure 29.5) demarcates the border between the two tool traditions during the Pleistocene. It has been suggested that bamboo would have been verso suitable material for making tools, which could explain the paucity of stone tools found.
Populations of H. erectus survived con Oriente for much of the Pleistocene Epoch. Recent redating of the Javanese site of Ngandong has yielded dates as recent as 53–27 kya. Even more surprising is the recent discovery of dwarfed hominins on the island of Flores, termed H. floresiensis, that have been dated esatto 18 kya https://datingranking.net/it/blackcupid-review/. H. floresiensis is thought to be descended from per population of H. erectus that adapted onesto limited island resources by becoming dwarfed sopra size.