Chapter 11, The Origins and Evolution of Early Homo habilis and Homo erectus
Homo habilis: The First Species of the Genus Homo
The Path to Humanness: Bigger Brains, Tool Use, and Adaptive Flexibility
First discovered by Louis Leakey at Olduvai Gorge
Name means “handy man”
Change took place 3.0–2.5 mya
Found in Tanzania, Kenya, Ethiopia, Malawi, South Africa
Homo habilis: The First Species of the Genus Homo
Homo habilis’s Adaptation: Intelligence and Tool Use Become Important
Anatomical evidence from the hand bones suggests precision grip.
Tools becoming fundamental to survival, unlike for australopithecines
Habitat Changes and Increasing Adaptive Flexibility
Spread of warm season grasses and increasing habitat diversity.
Skull and tooth morphology suggest dietary variability in Homo habilis.
Stone tools important for obtaining food resources as well as for processing foods.
Homo erectus
1) First to migrate out of Africa
2) First to use fire extensively
3) First to make complex tools, the handaxe
4) First true hunter, not a scavenger
Evolution of Homo erectus: Biological Change, Adaptation, and Improved Nutrition
Tool manufacture and the development of social structures to facilitate group cooperation
in hunting were critical.
Acheulian tool complex is represented by a variety of tools and tool materials.
Acheulian tools are more refined than the Oldowan tools.
Acheulian tools are bifacial. The most important is the handaxe
Homo erectus: Early Homo Goes Global
First discovered by Eugène Dubois in Java
Fossils date from 1.8–0.3 mya
African fossils dated to 1.8–0.3 mya
Nariokotome skeleton
An 80 percent complete skeleton
Short arms, long legs
Likely a young male
Would have stood 6 feet tall in adulthood
Cranial capacity over 900 cc
Homo erectus in Asia (1.8–.3 mya)
Fossils dated to 1.8 mya–0.3 mya
Earliest evidence found in Dmanisi, 1.7 mya, similar to East African Homo erectus
Also found in Indonesia, Sangiran, and China, indicating a rapid spread through Asia
Evolution of Homo erectus: Biological Change, Adaptation, and Improved Nutrition
Increase in body size is one main difference between H. erectus and H. habilis.
The increase took place rapidly, perhaps in as little time as 2.0–1.7 mya.
Climate change and its impact on the food supply may be one reason for the change.
Most significant impact was increased access to animal food (protein) from hunting.
Patterns of Evolution
Earlier forms have smaller brains than forms dated later.
Cranial capacity ranges from 650 cc to 1200 cc.
Skull robusticity declined.
Reliance on tools and tool use changed structure of face and jaws as a result of food
processing.
Changes in social structure and dispersal patterns, and increasing reliance on culture for
survival.
Homo erectus in Europe (800,000–400,000 yBP)
Stone tools, animal remains, hominid fossils
Stone-tool cut marks on animal and hominid fossils