Speciation

• Speciation


  The development of a new species
• Species


  A group of similar organisms that can reproduce to give fertile offspring
• Speciation


  Populations of the same species become so different that they can no longer successfully interbreed to produce fertile offspring
• Isolation and Natural Selection

  • Lead to Speciation
• Isolation


  Populations of a species are separated
• Causes of isolation


  • Physical barriers like floods and earthquakes
• Populations isolated by barriers


  Conditions on either side will be slightly different
• Natural Selection


  Different characteristics become more common in each population due to the environment being different on each side
• Individuals with characteristics that make them better adapted to their environment have a better chance of survival and so are more likely to breed successfully</b>
• The alleles that control the beneficial characteristics are more likely to be passed on to the next generation
• Speciation


  Individuals from the different populations will have changed so much that they won't be able to breed with one another to produce fertile offspring
• Wallace


  A pioneer of the theory of speciation
• Wallace independently came up with the idea of natural selection and published work on the subject together with Darwin in 1858
• Wallace's observations as he travelled the world provided lots of evidence to support the theory of evolution by natural selection
• Evidence from Wallace


  • Warning colours used by some species (e.g. butterflies) to deter predators