Chapter 7 : The Genetics Of Populations Flashcards
Assortative mating
Mating between members of a population that are more similar - more likely to share the same genotypes
Balanced polymorphism
Stable equilibrium that is polymorphic; both alleles are present
Balancing selection
Selection that leads to a balanced polymorphism
Directional selection
One allele is consistently favored over the other allele. Selection drives allele frequencies in a single direction toward an increasing frequency of the favored allele
Disassortative mating
Mating between members of a population that are more dissimilar- more likely to have different genotypes
Fecundity
Fixation
When an allele becomes fixed
Frequency-dependent selection
Frequency independent selection
Fitness associated with a trait is not directly dependent on the frequency of the trait in a population
Hardy-weinberg equilibrium
Hardy-weinberg model
Null model; says what happens to genotype frequencies when natural selection and other important drivers of evolutionary change are not operating.
Heterozygote advantage
Example: A1A2 heterozygote has a higher fitness than either the A1A1 or the A2A2 homozygous
Identical by descent
Inbreeding
Inbreeding depression
Continual inbreeding increases the frequency of rare deleterious recessive alleles and homorygotes carrying them
Mutation-selection balance
Overdominance
Heterozygote advantage
Population genetics
How the genotype frequencies in an offspring population are related to the genotype frequencies in a parental population
Selection coefficients
Parameter that describes the fitness reduction
Underdominance
Reverse of overdominance; the A1A2 heterozygote has a lower fitness than either the A1A1 or A2A2 genotype
Wright’s f-statistic
Quantifies the amount of inbreeding in a population. Tends to be higher in small populations.
