Lecture 8 Flashcards
Homo habilis age
~2.4-1.4mya (most ~1.8mya)
Homo habilis location
East Africa:
* Tanzania: Olduvai Gorge
* Ethiopia: Shungura Formation, Omo region; Hadar Formation
* Kenya: Koobi Fora/Lake Turkana
Homo habilis specimens
- Jaw fragments, skull parts, hand, foot and leg bones
Homo habilis body size
- Male ~37kg, 1.31m tall
- Female ~32kg, 1m tall
Homo habilis brain size
~500-650cm3 (slight enlargement?)
Homo habilis teeth
- Smaller teeth and jaw than afarensis but similar diet?
Homo habilis bipedal
- But still has relatively long arms compared to legs
Homo habilis tool maker
- Relatively secure associations of fossil remains with Oldowan tools
Homo habilis paleoenvironment
- Lived in both open and wooded environments at different sites
Homo habilis controversy
- Ancestral to H. ergaster?
- Is it a valid taxon or a collection of derived bits of Australopithecines and
primitive bits of other Homo species? - If valid, is does it really belong in Homo or in Australopithecus?
Homo rudolfensis age
- ~1.9mya
Homo rudolfensis location
- East Africa: Kenya, Lake Turkana
Homo rudolfensis specimens
- Skull, face, jawbones
Homo rudolfensis body size
Unknown
Homo rudolfensis brain size
~700-850cm3
Homo rudolfensis face
- Less prognathism than habilis
- Rounder cranium than habilis
- (though at least one reconstruction
found it to look a bit more primitive
than this!)
Homo rudolfensis teeth
- Extremely large teeth compared to
Homo habilis
Homo rudolfensis controversy
- Too large a difference from Homo
habilis to be sexual dimorphism? - Should we consider it an
australopithecine?
Tool use: who made tools?
- Once thought to have been Homo
habilis: ‘handy man’ - But date to 2.4-2.3mya i.e. after the now
earliest tools! - Now many australopithecines and
even paranthropines are in the frame
Problems with identifying which species used tools
Associations between fossils and
tools/cutmarked bones
* At many sites more than one fossil species
is attested to!
Hand bone evidence
* The vast majority of hand bones (some
could be foot bones) from this time period
are not securely linked to species!
Problems with archaeologically identify tools
- Are they actually stone tools, i.e. produced anthropogenically, rather than by natural processes?
- How good is the association? I.e. how close together are the fossils and tools found?
- What produced the association? Actual behaviour, or taphonomic effects? Does an association genuinely
demonstrate that the hominin represented used the stone tools found? - Are marks found on fossil bones genuinely anthropogenic?
- When evidence of stone tool use is not associated with a fossil hominin, is there any way of telling which species was
involved?
Problems with palaeoanthropologically identifying tools
- Hand bones are small and fragile and aren’t always preserved recovered
- Not particularly ‘diagnostic’, i.e. can be difficult to assign to individual species with certainty
- Shows potential for stone tool use: but assumes that precision grip and stone tool use are always associated, i.e. that
precision grip is an adaptation for/selected by stone tool use and not for something else, later exapted by stone tool
use!
Precision grip in humans
Human hand:
* Short, straight fingers
* Long, stout thumb
* Broad fingertips
Precision grip in chimps
Chimpanzee hand:
* Short, curved fingers
* Short thumb
* Weakly developed palm and
forearm muscles
* Narrow fingertips
* Wrist locks for stable knuckle-walking