Genetic diversity Flashcards
What is genetic diversity?
The number of different alleles of genes in a species or population
Why is a low genetic diversity bad?
The populations may not be able to adapt to a change in an environment and the whole population could be wiped out by a single event
How is genetic diversity in a population increased?
- Mutations in the DNA forming new alleles where some can be beneficial
- Different alleles being introduced into a population ie gene flow
What is gene flow?
Individuals from another population migrate into that population and reproduce
What does genetic diversity allow to occur?
Natural selection
What is a genetic bottleneck?
An event which causes a big reduction in a population
What does a genetic bottleneck reduce?
Reduces the number of different alleles in the gene pool and therefore reduces genetic diversity
What is the outcome of a genetic bottleneck?
The survivors reproduce and a larger population is created from a few individuals
What is the founder effect?
What happens when just a few organisms from a population start a new colony and there are only a small number of different alleles in the initial gene pool
What is the result of the founder effect?
The frequency of each allele in the new colony might be very different to the frequency of the alleles in the original population
What might the founder effect lead to?
Higher incidence of genetic disease
What can the founder effect be the result of?
Migration leading to geographical separation or if a new colony is separated from the original population for another reason
