Download Aust-Homo Differences

Two hominid patterns as proposed by Leakey and others
SoAn 101 Human Origins, Winter 2005
Genus Australopithecus
Genus Homo
(coexisted for a time with Homo)
(Ttransitional characteristics may be seen in
Homo habilis, H. rudolfensis )
Few if any stone tools
Brain size close to apes
Mainly vegetarian diet, little processing
Sex dimorphism 100%
Males in group unrelated; leave group
at time of sexual maturity
Males competitive
Humerofemural index 85-95%
Bipedalism + arboreal capability;
intermediate body shape
Gestation period correlates with brain
size as in other primates
Doubling of brain size from birth to
adulthood
Apelike dental growth pattern
“Ape grade” life history (age of
weaning, sexual maturity, life span,
etc.)
Lack of home base
Estrus, visual and olfactory sexual
cues
Hand-to-mouth food consumption
Stone tools
Brain size much larger than apes
Meat + high-end plant foods
Sex dimorphism 10-20%
Males related; stay in group
Apelike intelligence
Apelike vocal tract; flat basicranium
Apelike call systems
Males relatively less competitive
Humerofemural index 70-75%
Humanlike body shape and fully
dedicated bipedalism
Gestation period less than half that
predicted by general primate pattern
Tripling of brain size from birth to
adulthood
Humanlike dental growth pattern
“Human grade” life history: long
childhood, adolescent growth spurt,
prolonged life span
Home base
Continuous sexual receptivity and pairbonding
Food sharing, economic exchange,
provisioning
Increasingly abstract thought
(narrative binding)
Increasing basicranial flexion
Language: gestures, mimesis,
invented lexicon (eventually, syntax)