Understandings:
- Natural selection can only occur if there is variation among members of the same species.
- Mutation, meiosis and sexual reproduction cause variation between individuals in a species.
- Adaptations are characteristics that make an individual suited to its environment and way of life.
- Species tend to produce more offspring than the environment can support.
- Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring.
- Individuals that reproduce pass on characteristics to their offspring.
- Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
Applications and skills:
- Application: Changes in beaks of finches on Daphne Major.
- Application: Evolution of antibiotic resistance in bacteria.
Guidance:
- Students should be clear that characteristics acquired during the lifetime of an individual are not heritable. The term Lamarckism is not required.
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Theory of knowledge:
- Natural Selection is a theory. How much evidence is required to support a theory and what sort of counter evidence is required to refute it?
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