The following links offer some useful revision on Reproduction to support your learning:
BBC Bitesize – Evolution of Species
BBC Bitesize Video – Evolution of Species
West OS – Evolution of Species
Evolution of Species Summary Note
To help with your learning, you may also wish to try some of the following resources:
Evolution of Species Wordwall Game
Evolution of Species Quizlet Game
Evolution of Species PPQs & Marking Scheme
Within the National 5 Biology course, you will need to know:
- A mutation is a random change to genetic material.
- Mutations may be neutral, confer an advantage or a disadvantage to survival.
- Mutations are spontaneous and are the only source of new alleles.
- Environmental factors, such as radiation and some chemicals, can increase the rate of mutation.
- New alleles produced by mutation can result in plants and animals becoming better adapted to their environment.
- Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.
- Species produce more offspring than the environment can sustain.
- Natural selection or survival of the fittest occurs when there are selection pressures.
- The best adapted individuals in a population survive to reproduce, passing on the favourable alleles that confer the selective advantage. These alleles increase in frequency within the population.
- Speciation occurs after part of a population becomes isolated by an isolation barrier, which can be geographical, ecological or behavioural. Different mutations occur in each sub-population.
- Natural selection selects for different mutations in each group, due to different selection pressures. Each sub-population evolves until they become so genetically different that they are two different species.
