Evidence for Evolution

  • Biological populations

    • group of individuals of the same species

      • somewhat independent

      • often isolated by geography

  • Biological evolution

    • changes in biological population over the course of generation

      • inherited

  • Non-evolutionary changes

    • due to short-term environmental changes

    • not genetic

  • Natural selection

    • populations adapting to their changing environment

  • Microevolution

    • easily observed

    • within a population

  • Macroevolution

    • results in a new species

    • slowly over time

  • Theory of evolution

    • all species are descendants of a single common ancestor

  • Theory of the common descent

  • Charles Darwin

    • credited with bringing evolution to mainstream

  • Linnean Classification

    • organizes biological diversity and implies evolutionary relationships among organisms

  • Anatomical homology

    • similarities in skeletal bone structures

  • Convergent evolution

    • structural similarities in unrelated species with similar lifestyles

      • for example bats and bird wings

  • Vestigial traits

    • nonfunctional or greatly reduced traits

  • Developmental homologies

    • similarities in development processes from fertilized egg to adulthood

  • Molecular homologies

    • similarities in DNA sequences

  • Biogeography

    • distribution of species on Earth

  • Hominins

    • human and human ancestors

    • bipedal characteristics

      • used to walk on 2 limbs

  • Radiometric dating

    • ratio of radioactive elements to daughter products are used to estimate the age of rocks

  • Theory of common descent is supported by wide evidence