module 3: early homo & homo erectus

homo habilis

• trend toward larger brain/cranial capacity

• more globular skull

• more prominent forehead

• prominent brow ridges

• small face: becoming more orthognathic (right angle)

• small dentition: molars and premolars considerably smaller

• face sticks out less than australopithecus

• small body size similar to australopithecus

• foot specialized for bipedalism

• retains relatively long arms

• hand bones indicate some climbing

homo rudolfensis

• slightly larger cranial capacity than homo habilis

• more prominent forehead

• small brow ridges

• large, orthognathic face

• large molars

oldowan tools

• fist-sized cobblestones with sharp edges

• broken/chipped: a usable core and several sharp flakes used to slice meat off of bones

use of oldowan tools

• can slice meat off of bones

• can be used to pound things

• passive scavenging

unlikely use of oldowan tools

• hunting

• power scavenging

power scavenging

banding together to confront large predators— drive them off to take meat

passive scavenging

extracting marrow from long bones and brains from skulls

african homo erectus

• no sagittal keel

• smaller brow ridge

• smaller average brain size

asian homo erectus

• sagittal keel

• larger brow ridge

• larger than average brain size

homo erectus characteristics

• large cranial capacity— clearly a hominin

• position of foramen magnum & femur shape— clearly bipedal

nariokotome boy

• african homo erectus

• long legs relative to arms

• narrow pelvis

• 8-9 years old at death

• 5’-5’4”

• demonstrated that homo erectus had near-human proportions

acheulean stone tools

• much more sophisticated and hard to make

• teardrop-shaped handaxes

• bifacial

• similar proportions across time and space

• pointed end: cuts through meat

• rounded end: fits in palm

bifacial

core is flaked along two distinct sides

use of acheulean stone tools

butchering— disarticulating bones and heavy cutting

location of earliest homo fossils

ledi-gararu, ethiopia

hominin species living in east africa around 2.3 million years ago

• homo habilis

• homo rudolfensis

• paranthropus?

evidence that homo habilis and homo rudolfensis were different species

differences in skull shape

similarities between homo habilis and australopithecus

• small body size

• bipedality but also tree climbing

differences between homo habilis and australopithecus

• h. habilis:

  • larger cranial capacity

  • smaller molars and premolars

  • smaller, orthognathic face

  • rudimentary stone tools

  • smaller, less prominent brow ridges

• australopithecus:

  • larger, flat molars

  • smaller cranial capacity

  • prognathic face

  • rare/minimal tools

  • larger, more prominent brow ridges

location of biggest differences between homo habilis and australopithecus

skull

reason for trend towards smaller molars, premolars, and reduced mandible size in homo habilis and homo rudolfensis

• diet: ate fruits, more meat, and insects— easier to digest = reduced tooth size

when did homo erectus appear?

1.9 million years ago

where did homo erectus appear?

java, indonesia

homo erectus was the first hominin to…

• leave the continent of Africa

• control fire in hearths

• endurance running (tire out predators)

• human-like limb proportions (pelvis shape & IMI)

• brain over 1000 cm³

homo erectus traits setting them apart from other hominins

• extremely large brain size

• human-like body proportions

• smaller teeth and mandible

narikotome boy age

8-9 years old

when did homo erectus expand out of africa?

1.8 million years ago

where did homo erectus expand out of africa?

europe and asia

how was homo erectus able to expand so much (geographically)?

• new technology provided more access to meat, fueling brain growth, allowing for expansion of niches

• possibly due to association with acheulean tools

possible evidence for homo erectus controlling fire

• evidence of hearths

• stone tools near baked earth

• burned animal bones with h. erectus fossils

HOWEVER:

• no convincing evidence of fire until 500,000 years ago