Chapter 23 Flashcards
A cline is an example of what?
Geographic variation
What 5 processes lead to micro evolution?
- Mutations
- Sexual reproduction
- Natural selection
- Gene flow
- Genetic drift
What are the types of genetic drift?
Founder effect and bottleneck effect
What’s the only mechanism that leads to adaptive evolution?
Natural selection
What are the 5 conditions in Hardy-Weinberg equilibrium?
- No mutations
- Random mating
- No natural selection
- Large population size (no genetic drift)
- No gene flow
What is relative fitness?
Contribution individual gives to gene pool of next generation (relative to others)
Intrasexual selection vs intersexual selection
Intrasexual: members of one sex compete against each other
Intersexual: individual of one sex picky about choosing mate
What are the 3 patterns of natural selection?
Directional, disruptive, stabilizing
How is genetic variation preserved?
- Diploidy (hidden as recessive)
- Balancing selection (2 forms maintained)
What are the 2 types of balancing selection?
- Heterozygote advantage
2. Frequency-dependent solution (if phenotype is too common it will no longer be beneficial)
Why can’t natural selection create perfect organisms?
- Only acts on existing traits
- evolution limited by historical constraints
- adaptions are often compromises
- chance, natural selection and environment interact
What is average heterozygosity?
Percentage of heterozygous loci (measure of gene variability)