5.2: Natural selection

Teaching time: 3 hours Practical time: 0.5 hours (Finch Beak Practical)

key vocabulary

Retrieval practice and prior learning

5.1 L1 retrival practice

Draw and label a prokaryotic cell

The evolution of antibiotic resistant bacteria

A2: Evolution of antibiotic resistance in bacteria.

NoS: Use theories to explain natural phenomena—the theory of evolution by natural selection can explain the development of antibiotic resistance in bacteria. (2.1)

Exercise 1: Using the statements in U4-U7 explain how antibiotic resistance in bacteria may have evolved.

The evolution of finch beaks on Daphne Major

Essential idea: The diversity of life has evolved and continues to evolve by natural selection.

A1: Changes in beaks of finches on Daphne Major.

Exercise 2: Watch the HHMI interactive video and answer the questions presented in the film

The process of natural selection

U1: Natural selection can only occur if there is variation among members of the same species.

U2: Mutation, meiosis and sexual reproduction cause variation between individuals in a species.

Exercise 3: Outline how mutation, meiosis and sexual reproduction can cause variation within a species.

U3: Adaptations are characteristics that make an individual suited to its environment and way of life.

Exercise 4: Thinking back to the pentadactyl limb and the species that possess it, what adaptations do the different species have that have this limb?

U4: Species tend to produce more offspring than the environment can support.

U5: Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring.

U6: Individuals that reproduce pass on characteristics to their offspring.

U7: 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.

Guidance from the syllabus: Students should be clear that characteristics acquired during the lifetime of an individual are not heritable. The term Lamarckism is not required.