L11 Flashcards
What features did Tuang boy have?
- 1925 discovery of Tuang boy
- Brain small but more human than ape
- Small human- like canine teeth
- Bipedal (foramen magnum central)
Dart’s work in Africa
A.africanus
Robert Broom
- 1925-1935
- Robust form
2-1 ma
Major australopithecine sites
- Built on limestone
- Sinkholes trap animals and preserve them in caves
- Can also get washed into caves when it rains
- Some were killed by animals and dragged into caves etc
Predominantly east africa
A. boisei discovery
- Describes robust A. boisei
- Olduvai gorge Tanzania
- 1.75 Ma
- Rift valley
- Mary Leakey
- 1959
Homo habilis
- 1960-1963
- Build-up of terrestrial sediment
- Olduvai gorge
- 1.75ma
Problem with these discoveries
- Australopithecines co-existed with Homo
- Until now it was assumed that the ancestor Australopithecus evolved into the descendant Homo erectus
- Human evolution isn’t a linear progression it is a bushy evolutionary tree
- More than one bipedal species co-existing
1969
- More A. boisei discovered at lake Turkana, Kenya
- Always sediment accumulating
- Ashes can be dated
- Ideal for human preservation
- Huge variation in size of Lake
What species was Lucy?
A. afarensis
1970s Lucy
- Lucy - A. afarensis
- Pelvis and leg bone can calculate bipedal
- > 3ma
- Ethiopia
1978
- A afarensis footprints
- Laetoli, Tanzania
- Can work out stride length etc
1980s
A. aethiopicus
- Omo, Ethiopia
Recent discoveries
- Since the 1990s new Australopithecines have been discovered
- 14 species of Australopithecines now exist
- and Other genera of very early hominins (since divergence from chimpanzees 7 ma)
How many australopithecine species are now recognised?
14
Chad
- Inland
- Is our thinking influenced by a huge bias in the fossil record?
- Rift valley is not the cradle of civilisation, early findings in Chad question this
- Perhaps more found in rift valley due to perception
- Potential hypothesis of hominid evolutionary trees
- Cladogram can be made
- Cladogram shows sister group relationships
Between 3-2Ma in Africa how many hominin species co-existed?
-At least 6, these shared same or different habitats
-They were either Australopithecines or Homo
What habitat type did Australopithecines / Homo inhabit
Plains
mixed plains
woodland
forest
lake side
Were australopithecines bipedal?
Yes
- Essentially bipedal apes with modified dentition (ape- like from the neck up and human-like from the neck down) - They walked in a bent knee hip style
Footprints
- Stride patterns
What habitat did australopithecines predominantly spend their time?
In trees
Australopithecines probably spent much time in the trees
- Between human and chimpanzee
- Good at climbing trees
- Long phalanges
- Cranially orientated shoulder joint
- Funnel shaped thorax for climbing trees
- Hindlimbs meant for climbing
- Bipedal
- No designed for walking on four limbs
What is the difference between gracile and robust Australopithecines?
dental and facial adaptations to chewing: robust forms have robust jaws, more bulky chewing muscles and more prominent muscles attachments.
There is little difference in size of brain size (robust forms arguably have slightly larger brains)
Is there a difference in brain size across gracile and robust australopithecines?
Not really - arguably robust have somewhat larger brains
Robust forms ate more fruit
Jaw musculature and tooth wear provide evidence for diet
- More scratched up in robust forms
- Gracile forms have soft fruit, less damaged
Isotopic evidence
- Suggests some meat was eaten
Did australopitecines use tools?
- Co-existing so may have copied
- Tricky to tell
Did H habilis use tools?
Yes
