1. The Genus Homo
1.1. Characterized by: increased brain size, increased body size, less prognathic face, longer stride/shorter arms, and reliance on culture
1.2. Genus Homo Origin Hypothesis
1.2.1. The Scavenging Hypothesis
1.2.1.1. Hominin ancestors were not hunting but rather scavenging meat from carcasses
1.2.1.2. We know who ate first based on scanning electron microscope used to analyze faunal
1.2.2. Killer Ape Hypothesis
1.2.2.1. Raymond Dart- "Violence is innate in hominid ancestry
1.2.2.2. "Osteodontokeratic" (Bone, Tooth, and Horn) Culture
1.2.2.3. Human Ancestors: Savage hunters and bloodthirsty killers
1.2.2.4. Possible tools found in South African Caves
1.2.3. "Man the Hunter" Hypothesis
1.2.3.1. Tools used for Hunting animals
1.2.3.2. Homo were hunters
1.2.3.3. For many hunter/gatherer groups, hunting contributed relatively few calories to diet as compared to gathering
1.3. Bio-cultural trends in the genus Homo
1.3.1. Already bipedal, continued increase in brain size, reduced size of cheek teeth, increase body size, decrease in sexual dimorphism, change in limb proportions, prolonged life history, expanded geographic range, appearance and modification of stone tools
1.4. Brain Growth: pros and cons
1.4.1. Pros
1.4.1.1. More behavioral flexibility, higher problem-solving skills, improved communication, and improved social networking
1.4.2. Cons
1.4.2.1. High energetic cost, difficult birth, slower development, and increased parental investment
1.5. The Genus Homo
2. Homo Habilis
2.1. Cranial Features
2.1.1. Increased Brain size, reduced prognathism, larger forehead, and reduced robusticity
2.2. Dental features
2.2.1. Larger relative size if anterior teeth (incisors), reduced size of cheek teeth (premolars and molars)
2.3. Post-Cranial features
2.3.1. Ancestral traits, short stature, and short length relative to arm length
2.4. Homo Habilis
3. Homo Erectus
3.1. Cranial Features
3.1.1. Ancestral Traits
3.1.1.1. Large brow-ridges, receding forehead, no chin, and thick cranial vault
3.1.2. Derived Traits
3.1.2.1. Larger Brain, less prognathic face, sagittal keel, and nuchal torus
3.1.3. Post-Cranial Features
3.1.3.1. Long bones- robust with thick cortical bone, pronounced muscle markings, and very large