Evolution Of A Species Flashcards
What is mutation
Mutation is a random change to genetic material
How is mutation important
Mutation is spontaneous and are only the source of new alleles. This means that mutations are important in evolution since they provide variation.
What are the environmental factors for mutations
Radiation , chemicals and infectious agents
What are the benefits of new alleles being produced by mutation
It can result in plants and animals becoming better adapted in their environment.
What is adaptation
Adaptation is an inherited characteristic that makes an organism well suited to survival in its environment/niche
When does natural selection occur
Natural selection occurs when there are selection pressures (e.g. predator introduced, change in environmental conditions such as increased/decreased temperature or light intensity etc).
What happens to the best adapted individuals in a population
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.
When does speciation occur
Speciation occurs after part of the population becomes isolated by an isolation barrier
What is an isolation barrier
An isolation barrier can be:
Geographical (e.g. mountain range, sea, ocean, desert)
Ecological (e.g. ph, salinity, different habitats)
Behavioural
Where do different mutations occur
Different mutations occur in each sub population
What does natural selection select
Natural selection selects for different mutations in each group, due to different selection pressures
When do each sub-population evolve
Each sub-population evolves until they become so genetically different that they are 2 different species
