Evolution by Natural Selection

• What is meant by evolution?

  Evolution is the change in the inherited characteristics of a population over time.
• How does evolution take place according to the video?

  Through natural selection.
• What is the estimated number of different species of animals and plants on Earth?

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

  Only one percent.
• When did life first develop on Earth according to scientists?

  More than 3 billion years ago.
• What type of life forms were the first to develop on Earth?

  Very simple life forms, 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 genetic variation in a population?

  The differences in alleles among individuals.
• How might a colder environment affect a population of rabbits?

  Rabbits with thicker fur are more likely to survive.
• What happens to the alleles for thicker fur in a rabbit population over many generations in a colder environment?

  The alleles for thicker fur become more common in the population.
• What advantage do rabbits with better eyesight or hearing have when a predator moves into their area?

  They can detect the predator more easily.
• What is the definition of natural selection?

  Natural selection is the process where individuals with advantageous traits are more likely to survive and reproduce.
• What occurs when two populations of one species become so different that they can no longer interbreed?

  They become two separate species.
• What will be covered in more detail in a later video regarding evolution?

  Speciation.