3.6 evolution of species

• evolution

  the process by which new species or populations of living things develop from preexisting forms through successive generations
• mutations

  random changes to the organism's genetic material
• neutral mutations


  mutations with no effect on the organism, no impact on selective advantage
• disadvantageous mutations

  mutations that decrease selective advantage for the organism and can be harmful
• advantageous mutations


  mutations that increase selective advantage for the organism and can be beneficial
• mutagenic agents


  things that speed up rate of mutation (e.g, radiation, chemicals that damage dna in the cell)
• rate of mutation


  how fast or slow mutation occurs for that organism
• behavioural mutations


  genetic mutation that alters genes that control the way in which an organism behaves, causing their behavioural patterns to change
• physiological mutations


  genetic mutation that alters genes that control the way an organism acts
• variations


  different mutations in organisms
• natural selection


  survival of the fittest (best genes live)
• speciation


  in a population, an isolation barrier separates them, causing them to change, making new species that are genetically different
• isolation barriers

  a geographical, ecological, or behavioural barrier that separates the population of that species