Hominins (us) review…

• Defined by dental features, bipedal locomotion, large brain size, and tool making behavior

• Characteristics that developed at different rates, called mosaic evolution

Biocultural Evolution: The Human Capacity for Culture

• All aspects of human adaptation, including technology, traditions, language, religion, marriage patterns, and social roles.

• Culture is a set of learned behaviors; it is transmitted from one generation to the next through learning and not by biological or genetic means.

• Material culture is part of the cultural complex…

Oldowan Tool Industry

• The Oldowan is the first known industrial complex in prehistory. It takes its name from Olduvai Gorge, Tanzania

• Oldowan tool use is estimated to have begun about 2.5 million years ago (mya), lasting to as late as 0.5 mya.

• It is thought that Oldowan tools were produced by several species of hominids ranging from late Australopithecus to early Homo.

Chopping tool

Biface tool

Anthropologists who study this stuff…

• Paleoanthropologists. They study early humans. • Paleoanthropologists reconstruct the anatomy,

behavior, and ecology of our ancestors:• It is a diverse multidisciplinary pursuit seeking to

reconstruct every bit of information possible concerning the dating, anatomy, behavior, and ecology of our hominin ancestors.

• Locate early hominin sites, collect faunal remains and artifacts

Dating (relative)

• Relative dating methods. These tell you that something is older or younger than something else– Stratigraphy- based on the law of superposition,

which states that a lower layer is older than a higher one

– Flourine analysis, used to date remains of bone– Biostratigraphy – paleomagnetism

Dating (absolute)• Absoulte dating methods– Chronometric (Absolute) dating methods are based on

calendar years– K/Ar, or potassium argon method used to date materials

in the 5-1 mya range– Carbon-14 method used to date organic material

extending back to 75,000 years– Thermoluminescence– Uranium series dating– Electron spin resonance (ESR)

Early Hominoid – Where to Look?Rift Valley of East Africa

Southern Africa

3 Major Groups

Pre-australopiths (7-4.4mya)

Australopiths (4.2- 1 mya)Early Homo

(2.4 – 1.4)

How far back?

7 – 8 million years

70% of our history resides in Africa

Extensive changes in the last 10 years1992 3-4 million1998 4.4 2000 62003 7 million

Sahelanthropus tchadensis 6-7 mya

Beginnings to see Hominid trends•Brain case same as chimps 320-380cc

Sahelanthropus tchadensis 6-7 mya

Beginnings to see Hominid trends•Brain case same as chimps 320-380cc• The dentition, canines reduced

Sahelanthropus tchadensis 6-7 mya

Beginnings to see Hominid trends•Brain case same as chimps 320-380cc• The dentition, canines reduced•Brain case being moved back, tucked under the brain vault

Sahelanthropus tchadensis 6-7 mya

Beginnings to see Hominid trends•Brain case same as chimps 320-380cc• The dentition, canines reduced•Brain case being moved back, tucked under the brain vault•Primitive braincase, but hominoid facial features and canine teeth

Sahelanthropus tchadensis 6-7 mya

Beginnings to see Hominid trends•Brain case same as chimps 320-380cc• The dentition, canines reduced•Brain case being moved back, tucked under the brain vault•Primitive braincase, but hominoid facial features and canine teeth

•Probable Bipedal