Genetics and Populations - Populations and Evolution: Key Terms Flashcards
Allele frequency
The number of times an allele occurs within a gene pool.
Allopatric speciation
Speciation that occurs when biological population of the same species become geographically isolated form each other.
Directional selection
Selection for one extreme phenotype.
Disruptive selection
Selection favouring individuals with extreme phenotypes
Gene pool
All the alleles of all the genes of a population of a species.
Genetic drift
The change in allele frequencies that doesn’t depend on selective pressures.
Isolation
When part of the population of a species becomes separated into a different environment from the main population.
Mutation
A change in the DNA of an organisms that is heritable.
Stabilising selection
Selection against the extreme phenotypes.
Sympatric speciation
Speciation that occurs within a population in the same area as a result of reproductive isolation.
Selective pressure
A factor that drives selection.
Species
A group of organisms that share a common gene pool, so are able to interbreed and produce fertile offspring.
Hybridisation
A cross between different species.
Immigration
The movement of new individuals into an existing population.
Emigration
The movement of organisms from one area to another, resulting in the loss of individuals from a population.
