EVOLUTION- DARWIN

• DARWIN:

  • Expedition around the WORLD
  • Collected many PLANTS and ANIMALS
  • FASCINATED by VARIETY
  • Studied GEOLOGY and FOSSILS (species of EXTINCT are similar to species of EXISTING)
  • Developed "EVOLUTION by natural SELECTION"
• EVOLUTION BY NATURAL SELECTION:

  • Genetic VARIATION for any CHARACTERISTIC (e.g. giraffes have different sized NECKS)
  • Characteristics best SUITED to the ENVIRONMENT survive and breed SUCCESSFULLY (longer necks, can reach the most NUTRITIOUS leaves)
  • Offspring: survival CHARACTERISTICS are passed onto the next GENERATION
• ON THE ORIGIN OF SPECIES

  • Published in 1859

  Why was it CONTROVERSIAL and gradually ACCEPTED?

  • Not enough EVIDENCE
  • People believed in GOD, theories went against God's teachings
  • People didn't understand INHERITANCE (genetics was not understood until 50 years after the theory was PUBLISHED)
• LAMARCK'S THEORY:

  • Regular USE of a CHARACTERISTIC, there is a more developed, STRENGTHENED characteristic
  • EXAMPLE: Giraffe's NECK gets LONGER every time it gets LEAVES, offspring INHERIT the long neck, and hence later GENERATIONS get the long NECK

  PROBLEM:

  • Any changes in a LIFETIME, are not passed onto offspring, therefore his theory was INCORRECT