Early Homo Flashcards
When did australopithecus change into homo?
1.8 - 2.5 million years ago.
Body size and proportions changed, change in sexual dimorphism, change in brain size
Discuss the emergence of homo.
One species of australopithecus gave rise to the homo lineage around 2.6 million years ago.
Other australopithecine species go extinct, though some coexist with homo for a while (1.5 million years)
What was the geographical range of homo compared to australopithecines?
Australopithecines were largely restricted to Africa, genus homo will widen its range to include Eurasia
What were climates like?
Very seasonal in late pliocene/early pleistocene
What is Homo habilis?
- Found in association with tools in Olduvai Gorce, Tanzania
- Larger cranial capacity than australopiths
- Small teeth
- Fully parabolic dental arcade
- Less prognathic face
- Reduced jaws and chewing muscles
Where was Homo habilis found?
- Tanzania, Kenya, Ethiopia
- ## Up to 2.6 million years ago
What is early Homo postcranial anatomy like?
Australopiths
- Short stature
- Long arms
- Short legs
- Similar to Lucy
Early Homo are good bipeds, but since they retain australopith like features, they are also likely climbers
What are features of early Homo?
- Good bipedalists
- Likely climbers
- Brains are enlarged, but not by much
- Fast maturation like apes
- Use stone tools
What is “real” Homo?
Homo erectus
- No debate, this is a member of our genus
- Appear is lower Pleistocene (2 million years ago) which was a period of sharp cooling
- Widespread in eastern and south Africa
What are the features of Homo erectus?
- Primitive receding forehead, no chin
- Derived flatter face, more rounded skull, smaller molars, supraorbital and occipital torus
- Larger cranial capacity
What is the postcranium of Homo erectus?
- Long legs relative to arms
- More dimorphic than humans
- Challenging births (birth canal relative to skull size): intermediate life history
- Tooth eruption closer to human age: intermediate life history
What is a specific place where Homo erectus was found?
Dmanisi, Georgia
- 1.8 million years ago
- Five crania and postcrania
- Human like long lower limbs
- Very basic stone tools
Where is a specific place in Asia where Homo erectus was found?
- “Java Man”
- East Asia between 1.6 - 1.8 million years ago
- Long lived species
- Little change
Why was there a change from australopith to Homo?
Could be a change in diet. Reduction in gut size linked to higher quality diet which allows more investment in brain
What is evidence for dietary shift likely resulting in more meat eating?
- Reduced molar size (larger molars needed to break harder and tougher foods, humans usually eat softer foods)
- Archeological evidence (tools, cut marked and processed animal bones)
- Change in body proportions
