Evolution

• Evolution

  • The allele frequencies (within the gene pool) of a population can change over time due to processes such as natural selection
  • When the allele frequencies of a population change sufficiently over time, the characteristics of the species will also change
  • These changes can become so great that a new species forms
  • This process is known as evolution
  • Evolution can be defined as:

  The formation of new species from pre-existing species over time, as a result of changes to gene pools and allele frequencies from generation to generation
• • The formation of new species via the process of evolution has resulted in a great diversity of species on planet Earth
  • Theoretically, at the origin of life on Earth, there would have been just one single species, to begin with
  • This species evolved into separate species (i.e. new species)
  • These species would then have divided again, each forming new species once again
  • Over millions of years, evolution has led to countless numbers of these speciation events, resulting in the millions of species now present on Earth
• Evolutionary change over a long period of time has resulted in a great diversity of species

  A) speciation

  B) not

  C) different

  D) increases

  
• • The evolution of a new species can take a very long time and many generations
  • For organisms with a short generation time (such as bacteria), evolution can be observed far more quickly