18.4 effects of different forms of selection on evolution Flashcards
1
Q
what does stabilising selection select against?
A
extreme phenotypes
2
Q
how does the curve change in stabilising selection?
A
curve becomes narrower & taller
3
Q
when does stabilising selection occur?
A
environmental conditions being constant over a period
4
Q
what phenotype do directional selection select against?
A
other extreme
5
Q
how does the curve change in directional selection?
A
direction best adapted (left/right)
6
Q
what conditions causes directional selection?
A
changing environmental conditions
7
Q
what is selected against in disruptive selection?
A
average phenotype
8
Q
how is the curve affected in disruptive selection?
A
2 peaks / 2 seperate curve
9
Q
what environmental conditions results in disruptive selection?
A
environmental conditions taking on 2 distinct forms
