HUMAN EVOLUTION - EXAM MEMORISATION

Pelvis

• shorter and broader, lowers the centre of gravity and provides stability when upright

• bowl-like shape, which helps support internal organs during bipedal walking and assists in balancing the body weight over the legs

• shorter and broader, more SA for gluteal muscle attachement. Effective muscle attachement helps stabilise the body during each step by keeping the torso upright and balancing the weight over one leg at a time

Femur

• longer, which allows for longer bipedal strides, enables more energy-efficient movement and allows for bipedal walking over greater distances with less effort

• The valgus angle of the femur is positioned inwards towards the knees. This positions the knees directly under the body, which aligns with the feet and the centre of gravity, thereby reducing side-to-side lateral movement while walking, making bipedal walking more energy efficient

Knees

• positioned under the pelvis by the valgus angle. This means the centre of gravity is supported for better balance and allows one foot to be lifted while the rest of the body mass can be shifted to be balanced over the grounded foot

• knee joints are larger and stronger. helps absorb shock and support the extra weight during upright walking

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Condyle

lateral condyle is larger than the inner to support the additional weight force of walking bipedally - increases efficiency

Advantages of Bipedalism - long distance

• Energy-efficient over long distances. Travel further to find water/food/resources without using a lot of energy

Advantages of Bipedalism - thermo

• improved thermoregulation: walking upright reduced the surface area for direct sun hitting the body, helping with cooling

Advantages of Bipedalism - See

• walking upright could see over tall grasses and spot predators/see resources and plan movements

Advantages of Bipedalism - Free hands

carrying objects

• allowed hands to be free to carry food back to a home-base or to carry offspring and so increasing their survival against potential predators; for early tool manipulation; and for accessing a wider range of food sources

Disadvantages of Bipedalism - See

Vulnerability to predators: walking upright makes more visible to predators: slower than quadrupedal locomotion particularly in sprinting or chasing

Disadvantages of Bipedalism - Injury

Bipedal walking puts strain on the lower back, hips and knees. Birth canal is narrow, so labour is more difficult and complicated

Explain the selection pressure that led to bipedalism

climate became cooler and drier, forests turned into savannahs, so greater distances between resources

open grasslands, more exposed to sun

Positive Feedback relationship

power grip > tools > bone marrow > protein > brain expansion > tools complex > brain increased > culture evolution > loop

Tools & Food

wider range of diet/higher protein diet. Higher protein/energy foods led to brain expansion. Using tools meant hominins could access essential nutrients and calories needed for the energetically costly development and maintenance of a larger brain

Tools & Brain

tools became more complex, brain size increased (especially in areas related to planning, problem-solving, and motor skills). Brain expansion also enhanced speech, language, and social learning

pros of biological evolution

• Larger brains allowed for advanced cognitive abilities such as problemsolving, abstract thinking, and planning.

• develop complex languages, technologies, and social structures,

• Hand development allowed for the production of sophisticated tools and therefore access to higher energy nutrients that fuelled areas of the brain such as speech, abstract thought,

Disadvantages of biological evolution on culture evolution

• Traits that were once advantageous (e.g. a preference for high-calorie foods) may pose health risks in modern societies where food is abundant,

• The biological constraints of human ageing and lifespan limit how much cultural knowledge can be retained within a single generation. Important skills or information can be lost if not successfully transmitted before the death of knowledgeable individuals

Toes

• in-line big toe

• platform for support and push-off

• A heel-first contact followed by toe-off would increase stability and forward propulsion, which is typical of habitual bipedal locomotion.\

• strongheel region and a forefoot that can transmit forces during push-off,

improving walking efficiency over longer distances.

Spine

Define cultural evolution

transmission of knowledge, beliefs, customs, and practices within a population over time

Define biological evolution

changes in the genetic makeup of a population over successive generations, leading to adaptations to environmental pressures

Explain Oldawan Tools

H. Habilis

• simple partly shaped (around 6 blows) stones and flakes

• would have allowed them to access food that other species could have not, such as scavenging bone marrow.

• This may have helped provided protein necessary for brain development

Explain Acheulean Tools

H. erectus

• 50 blows, more refined

• hand axes to dig roots, hax tree branches

• for flakes, scrape and cut animal hides

• providing more food and perhaps defence from predators

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Explain Mousterian Tools

H, Neanderthals

• more refined, 150 blows

• more diverse in form and function

• blades were sharper, producing more blows

• Each tool was more specialised

• Rope may have been used to create spears for hunting

• Awls were made for punching holes in hide which, with hide lacings, could be used to make clothing, benefit for surviving cold environments in ice-age Europe

Explain Upper Palaeolithic

Homo Sapien

• finely worked, 250 blows

• Variety of materials, bone, ivory, antler

• diverse range of tools, including very finely worked and delicate items to be made

• Fishhooks and harpoons

• and needles, improving clothing and enabling the manufacture of shelters

• rapid expansion and colonisation of new areas, coastal