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Primates
flattened face opposable thumbs bicuspid teeth large brain relative to the body nails instead of claws prehensile hands
Mammals
fur /body hair milk-producing mammary glands teeth - incisors, canines, premolars lower jaw made of one bone breathe using lungs
Hominoids
No tail Broader/flatter rib cage Molars with five cusps
Hominins
Bipedalism Change in limb structure Increase in brain size/capacity
Functional trends
Less of a plant based diet Small canines/thicker jaw was for grinding food Spine more central into the skull Allowing for upright walking and aid with balance Larger birth canal Adapt to larger head size Spine being more S shaped More balance Defined heel bone Suggests upright walking Smaller arm to leg ratio Longer legs means more energy
Cognitive trends
Increased brain capacity Development of complex & spoken written language Development of reasoning and problem solving
What are some biological trends that led to cultural evolution
Percise grip led to fine motor skills - Ability to make fire, cook, make clothes, tools and art Structures involved with speech - Leading to communication and language Larger brain - Language and use of tools
What proves H.Sapiens evolved in Africa?
• Modern day Africans have the most mutated DNA, meaning they had more time to accumulate mutations
What is the Out of Africa theory
• Erectus evolved in Africa • Then migrated around the world • Neanderthals evolved from Erectus in Europse • Sapiens evolved from Erectus in Africa then killed them • Sapeins migrated to Europe, mated with Neanderthals then killed them
What suggests that we interbred with Neanderthals
Modern day Africans have no Neanderthal DNA, whereas modern day European and Asians have small amounts
Difference between A.Afarensis and H.Sapiens
• Sagital crest • Portruding eye ridges • Flatting of face • Thinner jaw • Larger cranium
Mitochondrial DNA
• Provides evidence of Out of Africa theory • 1-4% DNA shared with Neanderthals • Comes from maternal line • Mutates faster
Why might we choose nuclear DNA over mtDNA to find proof of interbreeding? mtDNA Mitochrondrial DNA
mtDNA comes from the maternal line (only one parent)
Why might we look at mtDNA?
The amount of mutations show the differences between species
Relate the changes in leg structure to bipedalism
**angled femur **from hip to knee brings knees closer together under the body’s centre of gravity central foramen magnum - head balanced directly over spine - better balance + walking upright pelvis - helps maintain stability when walking s-shaped spine - helps absorb shock and distribute body weight evenly during walking foot structure (arch, non-opposable big toe) - balance, shock absorption, and efficient propulsion during walking