GI: Genetic Diversity and Natural Selection Flashcards
Lots of different alleles means what for genetic diversity?
High genetic diversity.
Genetic diversity
Number of differnet alleles of genes in a species or population.
How is genetic diversity within a population increased?
- Mutations in the DNA - forming new alleles.
- Different alleles being introduced into a population when individuals from anotehr population migrate into them and reproduce - gene flow.
What allows natural selection to occur?
Genetic diversity.
Genetic bottleneck
An event that causes a big reduction in a population
How does a genetic bottleneck reduce genetic diversity?
- Reduces number of different alleles in gene pool
Founder effect
A few organisms from a population start a new colony and there is only a small number of different alleles in the initial gene pool.
Why might the founder effect occur?
Migration leading to geographical separation
New colony is separated from original population because of eg. religion
What does natural selection increase?
Advantageous alleles in a population
Describe the process of natural selection:
- Differential reproductive success means some individuals have an allele which increases chance of survival
- Greater proportion of next generation inherits beneficial allele
- Frequency of beneficial allele increases from generation to generation.
What are the 3 types of adaptations?
Behavioural
Physiological
Anatomical
Behavioural adaptations
Ways an organism acts increases chance of S+R
Physiological adaptations
Processes inside an organism that increases chances of S+R
Anatomical adaptations
Structural features of organism that increases chances of S+R
