Trends in Human Evolution

Biological Evolution

Changes in features coded for by DNA, passed down through generations

Cultural Evolution

Transmission of knowledge, passed down through learning, occurs quickly as one person can teach many. Homo habilis

Bipedalism

Habitual upright, walking on two limbs. Energy efficient method that favours low speed, long distance walking

Bipedalism

Advantages and disadvantages of BIPEDALISM

Free hands, heat regulation, less energy for long distances, see further / back ache, larger headed baby

Dentition

Number, size, arrangement of teeth in the skull and jaw

Broca’s region

Associated with creation of speech. Controls muscles of lips, jaw, tongue, soft palate and vocal chords

Bowl shaped hip girdle

Reduce stress on the hip that transmits body weight / Long bone to support abdominal organs

Thermoregulation

Ability of the body to keep cool

Valgus angle femur

Stronger, longer, angled inwards from the hip, knees nearly touch, shifts knees under hips = efficiency of balance, eliminates swagger

Wernicke’s area

Area of brain, comprehension of spoken words, listening

Opposable / Aligned big toe

Linear motion, shock absorption

Flat foot / Arched foot

Linear motion, shock absorption

Curved spine / S shaped spine

Linear motion, shock absorption

Large jaw, bigger teeth / small jaw, smaller teeth

More refined diet, no need for strong chewing muscles, attachment points, teeth

Strong neck muscles attached to nuchal crest / absent

Human skulls balanced above first vertebrate

Long arm : leg ratio / shorter arms

Not needed for brachiating

Curved, less mobile fingers = power grip / shorter, straighter fingers = precision grip

No need to grip branches, better for tool making

Cranial capacity APE

approx 450cc

Cranial capacity HUMAN

approx 1450cc, increased development, higher thinkiing

Oldowan Tools

H. habilis, simple multi-purpose, sharp end and flakes

Acheulean Tools

H. erectus, 50 blows, planning and time, processing of meat, improved access

Mousterian Tools

Neanderthals, 150 blows, specialised, finely worked, hunt and make clothes

Upper Palaeolithic Tools

H. sapiens, 250 blows, finely worked and composite, high skill and creativity, variety of uses

Who first used fire?

Homo erectus, controlled by Homo sapiens

WHY fire?

Protection, home base, light, warmth, making tools, more time, eliminate bad bacteria from food

Precision Grip

Intermediate hand, fingertips press, low power

Power Grip

hand, high power, force generation

Multiregional Theory

H. sapiens evolved independently in many places from H. ergaster/erectus over 1-2 mya, some fossil evidence in Europe 170,000 to short develop racial differences, require gene flow across continents, unlikely

Out of Africa Theory

H. sapiens evolved in Africa up until 170,000, then colonised, replacing other hominin species, fossil evidence, mtDNA, genetic similarities across races

Assimilation Theory

Modern humans evolved in Africa and spread across world, interbreeding with other hominins that left Africa earlier