5.2: Natural selection
Teaching time: 3 hours Practical time: 0.5 hours (Finch Beak Practical)
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.