Slide 1Slide 2What Defines a Hominine: LocomotionHominine traitsWhat Is a Hominine: DentitionWhy Did Hominines Emerge?Why Did Hominines Emerge?Slide 8The Primate Pattern1. Shortened snout w/ at least three types of teeth2. Eye sockets (orbits) that face forward (binocular vision)3. Orbits that are protected on all sides by bone4. Nails instead of claws (prosimian exception)5. Prehensile grasp – grasping hands and feet (human exception)6. Tendency toward vertical posture7. Relatively longer periods of infancy8. Brain with increased emphasis on vision vs. smellFigure 10.12 East African Tree CoverOur Origins, 2nd EditionCopyright © 2011 W.W. Norton & CompanyWhat Defines a Hominine: LocomotionBipedal: Getting Around Habitually on Two Feet–Associated skeletal changes):– Position of foramen magnum– Shape of pelvic bone (smaller ilium)– the foot – alignment of big toe with heel (lose prehenisile grasp)–Heavily muscled thumb; precision and power gripHominine traits•- long legs relative to body trunk• - stronger calf muscle•- more heavily muscled gluteus muscles•These are all in transition in earliest hominine species•What is NOT mentioned: a brain larger than body size would predict ; use of tools; languageWhat Is a Hominine: DentitionNonhoning Chewing: No Slicing, Mainly Grinding (rear large molars)–Refers to the way the mouth processes food–Lack of projecting canine, diastema–Parabolic tooth rows (vs. parallel)–Arched palateWhy Did Hominines Emerge?Charles Darwin’s Hunting Hypothesis–Bipedalism had freed the hands for carrying weapons.–Intelligence increased; size of canines diminished.–Tool production and use essential for development of human intelligence.–New evidence shows this not to be the case.Why Did Hominines Emerge?Bipedality Had Its Benefits and Costs–Bipedalism was a clear advantage to early humans ancestors.–It allows for a better view of the horizon, but also exposes the individual to predators.–Allows slow but extensive foraging for both plants and