Evolution by Natural Selection

• What should you be able to describe by the end of the video?

  What's meant by evolution
• How does evolution take place according to the video?

  Through natural selection
• How many different species of animals and plants are estimated to exist on Earth?

  Nearly 9 million
• What percentage of species that have ever lived on Earth are currently extinct?

  99%
• How long ago did life first develop on Earth?

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

  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
• What is an example of genetic variation mentioned in the video?

  Rabbits having different combinations of alleles
• 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 rabbit population
• What advantage do rabbits with better eyesight or hearing have when a predator moves into the area?

  They are more likely to detect the predator
• What is the definition of evolution as stated in the video?

  The change in inherited characteristics of a population over time through natural selection
• What occurs when two populations of one species become so different that they can no longer interbreed?

  They become two separate species
• What is an example of two different species of rabbits mentioned in the video?

  Normal-sized rabbits and pygmy rabbits
• Why can't pygmy rabbits breed successfully with normal-sized rabbits?

  Because they are so small
• What is the process of natural selection?

  • Variation exists within a population
  • Certain traits provide advantages in survival
  • Individuals with advantageous traits are more likely to survive and reproduce
  • Beneficial traits are passed on to offspring
  • Over generations, these traits become more common in the population
• What are the implications of speciation in evolution?

  • Leads to biodiversity
  • Results in the formation of new species
  • Can occur due to environmental changes or genetic divergence
  • Affects ecosystems and evolutionary pathways
• What resources can be used to study evolution by natural selection further?

  • Vision world book
  • Online resources and videos
  • Scientific literature on evolution