Leftovers Flashcards
Inbreeding increases
homozygosity
AA= yes
Aa= NO
aa= yes
does inbreeding cause evolution?
No, although genotype frequencies change, allele frequencies DON’T change in the population as a whole
sexual selection
nonrandom mating that occurs bc mate is chosen based on its physical/behavioral traits
genetic drift
reduces genetic variation by causing random loss or fixation of alleles
gene flow
may increase or decrease variation (depending on whether immigrants bring new alleles, or emigrants remove them)
mutation
increases genetic variation
Natural selection Patterns
- Directional Selection
- Stabilizing Selection
- Disruptive Selection
- Balancing Selection
Directional Selection
-changes the average value of a trait
-no effect on genetic variation
Stabilizing Selection
-reduces variation in a trait
-no effect on average value
disruptive selection
-increases variation in a trait
-decreases average value
balancing selection
-maintains variation in a trait
Bateman-Trivers Hypothesis
Pattern: sexual selection usually acts on males more strongly than females
fundamental asymmetry of sex
energetic costs of eggs are much greater than energetic cost of sperm
Consequences of fundamental asymmetry of sex
- female fitness is limited by ability to gain resources to produce eggs and raise offspring
- male fitness is limited by # of females they can mate with
Intersexual SS
between sexes (female choice)
- females prefer males that are well fed and in good health
