What are polygenic adaptive traits?
When multiple genes affects one trait
What are the three patterns of natural selection?
- Directional selection
- Stabilizing selection
- Disruptive selection
What is directional selection?
When natural selection is selecting for one of the extreme possible genotypes for a particular trait.
(when on extreme is advantaged for reproduction)
Bell gets moved
What is stabilizing selection?
When natural selection is selecting for the average of all possible phenotypes for a particular trait.
(narrowing: average is being favored)
What is disruptive selection?
When natural selection is selecting for both extremes of possible phenotypes for a particular trait.
What is sexual selection?
Alleles that allow the an individual to reproduce more easely are selected for.
What are two categories of sexual selection?
- Male-male competition.
(males compete with eachother to be the one able to mate with all of the females) - Female mate choice.
(males try to attract the most possible females)
What can sexual selection lead to? What is it?
Sexual dimorphisim.
When the two sexes of a specie look very differently from each others.
What is balanced selection?
When multiple alleles are maintained at relatively high frequencies in a pop.
What is called a population that balancing selection applies to have..
Balanced polymorphism
What are two situations that can lead to balancing selection?
Negative frequency-dependent selection.
(when the less frequen trait is selected for)
Heterozygote advantage.
(when the phenotype resulting from the heterozygous genotype are selected)
