Unit 2 Day 4 Flashcards
What is AD?
mutation rate
What is AR?
carrier rate
population genetics
the study of allele frequencies and changes in allele frequencies in populations
mutation rates
a measure of the rate at which various types of mutations occur over time. Mutation rates are typically given for a specific class of mutation, for instance point mutations, small or large scale insertions or deletions.
fitness
individual reproductive success and is equal to the average contribution to the gene pool of the next generation that is made by an average individual of the specified genotype or phenotype.
consanguinity
the property of being from the same kinship as another person. In that aspect, consanguinity is the quality of being descended from the same ancestor as another person.
hardy Weinberg principle
allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
population genetics
the study of allele (mutation) frequencies and changes in allele (mutations) frequencies in populations
-we are interested in deleterious mutations and a few beneficial ones
what are population genetics important for?
understanding allele frequency in populations and how those frequencies change
population sampling by phenotype leads to what?
estimates of allele frequency the underlying genetic mechanism
what are the basic principles of population genetics?
estimate mutation rates
determine fitness
effects of consanguinity
addition of new mutations to gene pool
hardy weinberg frequency
p+q=1
hardy weinberg equation
p² + 2pq + q² = 1
what is q in the hardy weinberg equation
q equals all of the alleles in individuals who are homozygous recessive (aa) and the other half of the alleles in people who are heterozygous (Aa)
what is p in the hardy weinberg equation
p equals all of the alleles in individuals who are homozygous dominant (AA) and half of the alleles in people who are heterozygous (Aa) for this trait in a population.
what can we learn from hardy weinberg principles?
- new mutations occur regularly
- most mutations are benign
- next gen DNA sequencing will determine whether the estimates we derive of mutation rates are correct
- by observing the number of cases of disease in a pop, it is possible to calculate rates of mutation for diff conditions
Assumptions of Hardy Weinberg principle
population matings are random
allele frequencies remain constant over time
why do allele frequencies remain constant over time?
- No appreciable rate of mutation
- All genotypes are equally fit (equal chance to pass alleles to next generation)
- No significant immigration/emigration of individuals with different allele frequencies
allele frequency estimation is useful for?
- autosomal recessive where you estimate carrier rates
- applied genetic counseling for couples (integrate family history)
what is the carrier frequency
2pq
what is prevalence of disease
q^2
why sex?
allows introduction of genetic variation to propagate new genetic traits
-benefits organisms who live in changing env., need to fend off disease, need to purge deleterious mutations
variation occurs due to ?
parental genomes
recombination in meiosis
sexual dimorphism
phenotypic differences btw males and females
reproductive organs, body habitus
