Evolution consequences: Inheritance, variation and evolution: Biology: GCSE (9:1)

• Natural selection


  A process where individuals in a population display variations that put them at a biological advantage, increasing the chances that these individuals will successfully reproduce and pass on their adaptive traits

  
• Evolution

  A change in the inherited characteristics of a population over time through the process of natural selection, can result in the formation of new species

  
• Survival of the fittest

  Individuals with characteristics most suited to the environment are more likely to survive and breed successfully

  
• Competition


  Organisms that are less-well suited to their environments will need to use more effort to compete and survive, these less adapted organisms are more likely to die without reproducing

  
• Extinction


  When there are no remaining individuals of a species left alive

  
• Cause of extinction

  Organisms unable to compete are at risk of extinction, where other organisms are better able to exploit the resources needed to survive
• Factors leading to extinction

  Fewer available mates, lack of resources such as food and water, predation or poaching by humans, competition with other species, environmental change, disease, catastrophic events

  
• Conservation


  The efforts of humanity to try to preserve endangered or vulnerable species and protect them from extinction

  
• Mass extinction


  The sudden extinction of many organisms that is caused by a catastrophic event such as volcanic activity, extreme global temperature change or asteroid impact

  
• 6th mass extinction

  Scientists believe we are currently experiencing a modern mass extinction, where many species are going extinct or are very likely to go extinct as a result of human activity and climate change

  
• Antibiotic resistance

  Antibiotic-resistant bacterial strains are more likely to survive and reproduce when exposed to antibiotics, where other bacteria will die and leave many resources unexploited

  
• Antimicrobial resistance

  Microbes other than bacteria have also been identified as being resistant to specific drug treatments
• Antibiotics


  A medication used to kill bacteria, antibiotics will not work for viral or fungal infections

  
• Causes of antibiotic resistance

  When exposed to antibiotics the majority of a bacterial population will be destroyed, however some individuals may survive and undergo mutations that can make them resistant to antibiotics

  
• Mutations


  Bacteria can undergo genetic mutations that can affect their characteristics, as bacteria reproduce rapidly these mutations can quickly spread in a population
• MRSA


  A bacterial strain that is resistant to antibiotics and is prevalent in hospitals where it is very difficult to treat

  
• To reduce the rate of antibiotic resistance

  Doctors should not prescribe antibiotics inappropriately, patients should complete any courses of antibiotics to prevent mutations, farms should not use antibiotics on livestock

  
• New antibiotics

  The development of new antibiotics is costly and slow, it is unlikely to keep up with the emergence of new resistant strains