Models on WHY?• Why we became bipedal (6 hypotheses)

Efficient bipedalism as the primary form of locomotion is seen only in hominins.

BECOMING HUMAN PART 1• NOVA

Becoming Human review…• Lucy and bipedalism– Habitual vs. Obligate Bipedalism– Ossa Coxae– Foot as stable support– Longer legs– Full knee extension

Hominins (us) are Hominoids

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

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)

PALEOANTHROPOLOGYThe “Study of Old Humans”

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

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)

Lucy 3.7 –3.5 mya

Don Johanson Dicovered in Hadar in 1974

Lucy in combination w/ Leakey footprints tell us about locomotion and stature

Lucy 40% of skeleton, one of three most complete, Pre-100,000

Accurate Dates due to Volcanic Ash layers

Laetoli (Ash Footprints)

Discovered in 1978

1. Convergent Big Toe

2. Clearly Bipedal

3. Arch

4. Slow Moving “Strol”

5. Short Stride

Laetoli (Ash Footprints)