Homo ergaster WT 15000 Nariokotome, Kenya 1.6 mya

Homo ergasterWT 15000 Nariokotome, Kenya

1.6 mya

Olduwan chopperGadeb, Ethiopia2.4-1.5 mya

Australopithecus afarensis

A.L. 200-1, Hadar Ethiopia~3 mya

Homo sp. early Homo

A.L. 666-1, Hadar Ethiopia

2.3 mya

Australopithecus afarensisAL 288-1, Lucy

Hadar, Ethiopia, 3.2 mya

Australopithecus afarensisHadar, Ethiopia, ~3 mya

• A. afarensis endocranial capacity = 387-550• consistent morphologies – more apelike than other

australopithecines• dimorphism = sexual or increase in size through time?

chimpanzee & A. afarensis share•subnasal prognathism•large anterior dentition•diastema between lateral incisor & canine•confluence of temporal & nuchal lines•broad pneumatized cranial base•note that A. afarensis is distinct from other australopithecines in these traits

the 3rd premolar (P3) in A afarensis = intermediate between chimpanzee 7 modern human morphologies

Australopithecus africanusSts 71, Sterkfontein South Africa, 2.5 mya

Australopithecus sebida, 1.9-1.78 mya South Africa

•endocranial capacity= 420-450 cc•not greater than A. africanus•likely contemporaneous with H. ergaster

Australopithecus sediba

Paranthropus boiseiOH 5

1.8 mya

Homo habilisKNM ER-1813

Koobi Fora, Kenya

1.9 mya

Homo habilis - “handy man”

•mixed morphologies•not a clearly identifiable taxon•potentially represent multiple species•demonstrates selective pressures & changes

KNM-ER 1470, Kenya1.8-1.9 mya

KNM ER-1813 Kenya

1.9 mya

Homo habilis from

Koobi Fora

Homo habilisKNM ER-

1813 Koobi Fora, Kenya

1.9 mya

•small brain (~510 cc)•small teeth•australopithecine-like

Homo habilisKNM-ER 1470, Koobi Fora, Kenya

1.8-1.9 mya

Homo habilisKNM-ER 1470,

Koobi Fora, Kenya

1.8-1.9 mya

•large brain (~750 cc)•large teeth

Homo rudolfensis

“solution”= create another species

Homo ergasterendocranial

capacity = 870 cc

KNM ER 15000, Homo

ergaster, Nariokotome,

Kenya, 1.5 mya

Homo ergasterWT 15000 Nariokotome, Kenya

1.6 mya

Homo ergaster, Kenya, 1.6 mya

Homo ergaster~1.8-1.7 mya•possibly as late as 600 kya•considered ancestral to all subsequent Homo•increased brain size•increased body size•possibly more modern growth & development

Homo ergaster, Swartskrans, South Africa,1.8-1.9 mya

•contemporaneous with P. robustus in South Africa•dental eruption may be more modern•tooth crown formation may be more apelike

Australopithecus afarensis

L.H.-4, Laetoli, Tanzania3.6 mya Homo ergaster

KNM-ER 992, Kenya~1.5 mya

Homo ergaster, OH9, Olduvai Gorge, Tanzania, ~1.2 mya

Homo ergaster KNM-ER 3733, Koobi Fora, Kenya

1.75 mya

Homo erectus, Daka, Middle Awash Valley,

Ethiopia, 1-0.8 mya

resembles H. erectus in:•endocranial capacity =995 cc•broad base•sagital keelresembles H. ergaster in:•thin vault bones•height of vault•no occipital torus

H. Erectus or H. ergaster?,

Dmanisi, Georgia,

1.75-2.0 mya

Reorganization of :•limb proportions•longer legs•shorter arms•trunk dimensions•ribcage=more barrel shaped •gut area reduced

Brain

•not just an increase in size•differences in brain organization•cognition•thought•emotions•brain is a costly tissue•affects dietary needs•growth & development•birth

Comparative primate allometric expectations of proportions of human

organ mass

Human gut lengths short•compared to other primates of our size•longer gut lengths associated with processing high volumes of low-quality foods

Selection on hominins appears to be:•on increased cognition-grow the size of the brain•support that through higher quality foods•and reduction in another costly tissue•the gut•is selection primarily on brains?•or on increased dietary quality?

complex interrelationship between diet, brain size increase, behavior, & morphology

antelope humerus, Olduvai Gorge, Tanzania, ~1.8 mya

David Brill

FLK “Zinj” site in Olduvai Gorge, Bed 1 deposits, 1.8-1.76 mya •~100 bones show cutmarks-percussion marks•3,500 large mammal bones•2,500 Olduwan tools•hunting?•scavenging”?•carnivore remains? •natural death?•

C. K Brain

•questioned associations of bones with australopithecines as food remains•initated modern taphonomic research

Taponomycomplex sources of deposition of animal bones in sites with archaeological remains and hominin fossils•natural death•carnivores•geologic accmualtion•hominins

Cutmarks•identifying stone tool marks•natural scratches•overprinting•excavator marks•using them to understand potential butchering patterns

Cladistics

Can get varying relationships depending on emphasis of different traits

multiple contemporaneous hominins-what specializations?

Paranthropus boisei

Homo habilis

Homo rudolfensis

Homo ergaster

Scientific American 8/25/2003:22-23

Homo ergasterWT 15000 Nariokotome, Kenya

1.6 mya

Acheulean handaxe