EVOLUTION

• What is evolution?

  Changes in inherited traits over generations
• Why is evolution important for organisms?

  It allows organisms to adapt and survive
• What are the evidences of evolution?

  • Fossil records
  • Comparative anatomy
  • Embryonic environment
  • Genetic information
  • Biogeography
  • DNA sequence comparison
  • Analogous organs
  • Transitional forms
• What is the geological time scale?

  A record of Earth's history based on life-forms
• What are geochronologic units?

  Units based on fossil types in rock
• What are the divisions of the geological time scale?

  1. Eons: Longest subdivision
  2. Eras: Next longest subdivision
  3. Periods: Based on life types
  4. Epochs: Shortest subdivision
• What is the earliest eon in the geological time scale?

  The Precambrian eon
• How are eras defined in the geological time scale?

  By spanning tens to hundreds of millions of years
• What are periods in the geological time scale based on?

  Types of life that existed during that time
• What are epochs in the geological time scale?

  Shortest subdivisions that vary by continent
• What are fossil records?

  Traces of organisms preserved in the past
• How do fossils relate to extinct species?

  They document existence of now-extinct species
• What are imprints in fossil records?

  Shallow external molds of tissues
• What are compression fossils?

  Preserved tissues in sedimentary rock
• How are the ages of fossils determined?

  Through relative and radiometric dating
• What is relative dating?

  Comparing the age of rock layers
• What is radiometric dating?

  Determining age using radioactive isotopes
• What is carbon-14 used for?

  Determining the age of rocks and fossils
• What is comparative anatomy?

  • Study of similarities and differences in structures
  • Types of structures:
  • Homologous structures
  • Analogous structures
  • Vestigial structures
• What are homologous structures?

  Body parts of different organisms with same origin
• What are analogous structures?

  Body parts that perform the same function but differ in origin
• What are vestigial structures?

  Body parts that are useless remnants from ancestors
• What is embryonic development?

  The life cycle portion after fertilization
• How do similar embryos support evolution?

  They suggest a common ancestor among organisms
• How do small mutations in DNA affect evolution?

  They lead to the evolution of new species
• What are the theories of evolution?

  • Lamarck's theory
  • Darwin's theory