1. Introduction to Hominins and the Bipedal Adaptation Pre-Australopithecines, Australopithecines, Genus Homo

3. Three groups on the Human Evolutionary Line:
“Pre-Australopithecines”
Ardipithecus ramidus
Sahlenthropus tchadensis
Ororrin tugenesis
Primate to Human transition

4. “Pre-Hominins” Australopithecines Primitive Gracile Robust
Anamenis, Afarensis
Gracile
Africanus
Robust
Robustus, Boisei, Aethiopicus*

5. Features of the Hominins
Smooth or Angular cranium?
Narrow or Broad face?
Zygomatic flare=wide cheek bones
Facial profile
Dentition
Canines (reduced size)
Generalized omnivore or vegetarian
Sagittal Crest?
Reduced prognathism
Chin
Postorbital Constriction

6. Bipedal Adaptation: Why change?
Benefits
Problems

7. Bipedal Adaptation: What changes?
Must maintain balance
Drastic structural/anatomical alterations
Body weight over just the lower limbs
Center of gravity
Striding Gait
Stance vs. Swing phase

8. Anatomical Features of Bipedalism
Cranium
Angle of foramen magnum
Angle of Femur
Center of gravity

9. Biped: Vertebral Column
S-shaped
Two opposing curvatures
stability

10. Pelvis In bipeds, basin shaped
Supports internal organs pulled by gravity

11. Lab
Either Lab 13.1 or Handout
Lab 13.2, 13.3
Self test 13.1