evolution + variation

• How does evolution take place according to the video?

  Through natural selection
• How long ago did life first develop on Earth?

  More than 3 billion years ago
• What were the first life-forms on Earth described as?

  Very simple, such as single cells
• What is the process called where all species of living things have evolved from simple life forms?

  Evolution by natural selection
• If the environment gets colder, which rabbits are more likely to survive?

  Rabbits with alleles for thicker fur
• What happens to the alleles for thicker fur over many generations?

  They become more common in the population
• How does the introduction of a predator affect rabbit populations?

  Rabbits with better eyesight or hearing survive
• What is the definition of evolution provided in the video?

  Change in inherited characteristics over time
• What occurs when two populations of one species become so different?

  They can no longer interbreed
• What is the process of natural selection?

  • Variation exists within a population
  • Certain traits provide survival advantages
  • Individuals with advantageous traits reproduce more
  • Beneficial traits become more common over generations
• What are the implications of speciation?

  • Two populations become distinct species
  • They can no longer interbreed
  • Genetic divergence occurs over time
• What are the key factors in evolution by natural selection?

  • Genetic variation
  • Environmental pressures
  • Differential survival and reproduction
• what are genetic variations caused by

  mutations
• what is a mutation

  change in DNA base sequence
• is it rare that a mutation will lead to a new phenotype

  yes
• how can a new phenotype be beneficial

  can be beneficial if environment changes and can lead to rapid change in the species
• evolution definition

  change in the inherited characteristics of a population over time through natural selection, may result in formation of new species
• evolution theory

  all species of living things have evolved from simple life forms that first developed more than 3 billion years ago