Evidence for evolution

Darwin’s observations

  • all organisms over-reproduce

    • far more offspring are produced than are required to keep the population at a steady size

  • population numbers tend to remain fairly constant over long periods of time

  • organisms within a species vary

  • some of these variations are inherited

  • there is competition for survival

  • individuals with characteristics that best adapt them for the environment are most likely to survive and reproduce

  • if these characteristics can be inherited then the organisms will pass the characteristics onto their offspring

Alfred Wallace

  • independently came to the same conclusions as Darwin

  • presented their work in two papers to the Linnean society in 1858

Further evidence supporting Darwin

  • Palaeontology

    • palaeontology

  • Comparative anatomy

    • comparative anatomy - pentadactyl limb

  • Comparative biochemistry

    • highly conserved molecules are studied to see when functional changes occur

    • neutral changes won’t affect function so shouldn’t affect natural selection

    • comparative biochemistry - DNA