natural selection

• bipedal

  walking upright on two legs
• evolution

  slow and continuous change of an organism from one generation to the next
• natural selection

  best adapted organisms survive and reproduce, passing their allele to their offspring
• mutation

  change to the gene caused by a mistake when copying DNA base pairs during cell division
• survival of the fittest

  way to describe evolution by natural selection (charles darwin)
• evolutionary tree

  represents the relationships beteen organisms

  
• lucy - australopithecus afarenisis, 3.2 million years old

  • bipedal
  • long arms, short legs
• ardi - ardipithecus ramidus, 4.4 million years old

  • no sharp teeth
  • long arms
• turkana boy - homo erectus, 1.6 million years old

  • walked fully upright
  • small brain (bigger than lucy's)
• MRSA

  • natural variation in the population
  • some staphylococcus are resistant to antibiotics due to mutation
  • weaker bacteria die out when treated
  • resistant bacteria survive and multiply
  • mutation is passed on and only resistant staphylococcus are left.
• reasons antibiotic resistance has emerged:

  • overuse of antibiotics
  • not finishing your course
  • poor hospital sanitation
• tools show a link between brain size and the development of complex tools
• domain - eukarya

  kingdom - animalia

  phylum - chordata

  class - mammals

  order - primates

  family - hominidae

  genus - homo

  species - sapiens