Natural Selection Flashcards
1
Q
Natural selection
2
A
- certain heritable traits make more offspring
- changes genetic pop over time
2
Q
Requirements natural selection
3
A
1) variation in pop
2) trait heritable
3) variation in trait associated with diff fitness
3
Q
Adaptations
3
A
- heritable traits that increase ability survive/ reproduce compared without trait
- natural selection only mech result increase f adaptive traits overtime
- start mutation, increase f pop with natural selection
4
Q
Is natural selection random?
2
A
No
- individuals survive/reproduce not random (contrast genetic drift)
- alleles help survive more likely to be common
5
Q
Is natural selection perfect?
A
No (good enough)
6
Q
Do individuals evolve with natural selection?
A
No
- individuals don’t evolve, only more/less successful reproducing
- only pop evolve
7
Q
What is directional natural selection?
3
A
- favors individuals at extremes at one end of spectrum
- selects against other phenotype
- reduces diversity
8
Q
What is stabilizing in natural selection?
3
A
- Favor intermediate
- against extremes
- variation reduced
9
Q
What is distributive natural selection?
A
- favor both extremes
10
Q
What is sexual selection?
3
A
- non- random mating
- females (less males ) determines which alleles get passed on (opposed environment)
- individuals with certain inherited traits more likely reproduce and pass on alleles
11
Q
Ecological selection
A
- environmental determines which alleles get passed on
12
Q
2 mechs for sexual selection
A
- competition mates ( intrasexual)
- mate choice (intersexual)
13
Q
Intrasexual selection
4
A
- males competes against each other ( can be costly )
- seed signals ability to competes /provide
- sneaky males
- invest heavily in sperm
14
Q
Intersexual selection
A
- males fitness limited by access female , females must be picky though
- if mother invest more offspring , more selective
15
Q
Female vs make fitness
A
Female: fitness of babies
Males: how much they procreate
