Human Evolution

Human Evolution

Cultural Evolution
1. Use of Tools
  1. Oldawan - simple stone tools. Round stones with one end chipped. Used to chop and scrape. First kind of tools to develop, Homo habilis
  2. Acheulian - tear drop like stones, double edged hand axes. Used as hand axes and cleavers by Homo erectus and Homo heidelbergensis
  3. Mousterian - sophisticated tool, finely worked made of stone but may have other materials attached as handles. Required skill and learning. First used by Neandethals.
  4. Upper Paleolithic - further refined tools. Large variety of tools for many different purposes. Shaped to fit into handles. Made of many of many materials including bone. First used by Homo sapiens and Neanderthals.
2. Social Behaviour
3. Abstract Thinking
  1. Communication
    1. Broca's and Wernicke's area of the brain provide evidence of development in speech and communication.
    2. Speech resulted in better hearing and listening skills.
  2. Art
    1. Pictures and symbols on cave walls, carvings in bone and antlers, clay statues show evidence of communication and abstract though.
4. Food Gathering
  1. Hunter-gatherer
    1. Nomadic, following seasonal availabilty of plants and animals
    2. Division of labour between males and females.
  2. Domestication of Plants and Animals
    1. A more settled lifestyle. Change due to population expansion, food shortage, climate change at end of ice age and required to be near constant source of water.
    2. Wild wheat and barley grew. Grains at first gathered but later sown as seeds. Evidence: sickle-shaped wooden tools with microliths (very small, sharp stone flakes) set into them - used for harvesting and quern stones - used for grinding grain.
    3. Advantages: able to grow more food, surplus food could be traded for other things such as tools, more time available for skill specialisation.
      1. Disadvantages: monocultures = less genetic variation, prone to disease, malnutrition due to little variation, issues storing food over winter, climate dependent.
    4. Animals - fossil evidence of animals all around same age while animals that are killed hunting tend to be various ages. Advantages = ready supply of milk and meat that is fresh, traded for other things, used to carry heavy loads. Disadvantages = selective breeding so less genetic variation therefore susceptible to disease which humans could catch.
5. Fire
  1. Cooking made food softer and easier to digest.
  2. Kills many microbes, reducing risk of disease.
  3. Detoxify some plant toxins.
  4. Keeps predators away.
  5. Source of light.
Biological Evolution
1. Bipedalism
  1. Valgus Angle - the angle of the femur. Shifts knees under centre of gravity. Helps with balance and walking.
  2. Pelvis - short and shallow, cup shaped to support internal organs. Better attachment for larger leg muscles.
  3. Position of foramen magnum allows head to be vertical and reduces need for large neck muscles as gravity assists.
2. Skull Changes
  1. Foramen Magnum - moves from angle to vertically aligned.
  2. Saggital and Nuchal crest - become much smaller, no longer require very large neck muscles.
  3. Brow ridge, slopping face, zygomatic arches all become less prominent. Chin appears.
  4. Teeth change from 'U' shape and parallel to a 'V' and more parabolic.
3. Manipulative Ability of the Hand
  1. Opposable thumb - allows for precision grip
  2. Fine motor control, able to maniqulate small objects

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	Criado por Millie Johnston aproximadamente 9 anos atrás