Key Concepts in Human Evolution and Bipedalism

Phases of bipedal walking

Stance Phase (Heel strike → Foot flat → Mid-stance → Heel-off → Toe-off) and Swing Phase (Early → Mid → Late swing).

Integral body part for upright walking

The pelvis, which is shorter and broader in humans for balance and support.

Theory for bipedalism

Energy Efficiency Hypothesis.

Flaw of bipedalism theory

Doesn't explain why climbing advantages were forsaken.

Difference between hominid and hominin

Hominid includes all great apes; hominin refers specifically to humans and their ancestors after the chimpanzee split.

First three oldest hominins

Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus.

Lumpers vs. splitters

Lumpers group fossils into fewer species; splitters classify fossils into more species based on minor differences.

Characteristics of Australopithecus

Small brain size (300-500 cc), adaptations for climbing and walking, reduced canines, and thick tooth enamel.

Gracile vs. robust Australopithecus

Gracile: Smaller teeth, generalized diet. Robust: Larger molars, sagittal crest, specialized for tough plant material.

Key features of the Homo genus

Larger brain size, tool use, and obligate bipedalism.

Key characteristics of early Homo species

Habilis: Tool use, precision grip. Ergaster: Long legs, endurance running. Erectus: Acheulean tools, migration. Naledi: Small brain, deliberate burials. Heidelbergensis: Brow ridges, hunting. Neanderthal: Cold adaptation, symbolic behavior. Archaic sapiens: Transition to modern behavior.

Importance of stone tools

They reveal cognitive abilities, diet, and social organization.

Five modes of tool industries

Mode 1: Oldowan - Simple pebble tools. Mode 2: Acheulean - Hand axes. Mode 3: Mousterian - Prepared cores. Mode 4: Upper Paleolithic - Blades. Mode 5: Microlithic - Composite tools.

Hunting as a learned feature

It requires knowledge of animal behavior, tracking skills, and cultural teaching.

Disadvantages of a bigger brain

High energy demands, prolonged dependency, and increased childbirth risks.

Evidence for modern human behavior

Examples include cave art, personal ornaments, burials, and clothing evidence.

Carpentered world hypothesis

People in rectilinear environments perceive straight lines and angles differently than those in natural environments.

Difference between norms and values

Norms are rules of behavior (e.g., shaking hands); values are core beliefs (e.g., honesty is important).

Subcultures, countercultures, dominant cultures

Subcultures: Distinct groups (e.g., skaters). Countercultures: Oppose mainstream norms (e.g., hippies). Dominant culture: Prevailing norms (e.g., mainstream media).

Endocasts

Casts of braincase interiors that reveal brain size and structure.

Types of 'fossilized' brains

Natural endocasts, molded endocasts, impressions, fossilized braincases, and virtual models.

Music and humans

It fosters social cohesion, emotional expression, and cultural transmission.

Factors under bone trauma

Fractures, dislocations, cuts, and impact marks.

Puppe's Rule

It explains fracture patterns based on the sequence of impacts.

Types of long bone fractures

Transverse, oblique, spiral, and comminuted fractures.

Three force fracture types

Blunt (wide-area trauma), sharp (focused cuts), and ballistic (high-speed trauma).

Musculoskeletal markers

Changes from repetitive activities that reveal behavior, occupation, or tasks.