Evolutionary Genetics Flashcards
what is a population? what is its gene pool?
group of individuals with a common set of genes living in a geographic area
-gene pool is all alleles present in the population
rules for HWE
-population size is infinite
-random mating occurs
-natural selection does not operate
-gene flow does not introduce new alleles
-mutation does not introduce new alleles
-genetic drift does not occur
two receptors for HIV? how do ARGs interact with them?
CD4 and CCR5
ARGs interphere with viral cell entry
in late stage infections HIV uses what?
CXCR4
Fitness definition?
denotation and range?
an individual organisms genetic contribution to the next generation
- 0-1 range(no reproduction-high reproductive sucess)
how does selection of an allele interact with frequency of deleterious alleles and fitness?
usually stabilizing: selects against deleterious mutations
3 types of natural selection and their impacts
Directional: shifts towards one parental phenotype
Disruptive: shifts towards both parental phenotypes with low chances of the blended phenotype
Stabilizing: shifts away from both parentals towards the blended phenotype
what alone acts to create new alleles and change allele frequency?
mutation
how does gene flow lead to admixed population? what is another term for it?
addition of new organism to an existing population
also known as migration
immigration vs emigration
Immigration: movement Into a population
Emigration: Exiting a population
what is genetic drift? what 2 main effects that can be applied?
when the number of reproducing individuals in a population is too small to ensure that all alleles will be passed onto the next generation
-founder events and bottlenecks
examples of population bottlenecks
bison
2 types of non random mating
positive assortive: similar genotypes more likely to mate
Negative assortive: dissimilar genotypes more likely to mate
3 degrees of relatedness
1st degree: parents and children(50% shared alleles)
2nd degree: grandparents and grandchildren, siblings (25% shared alleles)
3rd degree: aunts/uncles, first cousins (12.5% shared alleles)
inbreeding and inbreeding depression
Inbreeding: mating between related individuals
Inbreeding depression: lower means of fitness in inbreeding populations
2 models of hominin evolution
multiregional hypothesis(MRE)
recent African origin(RAO)
rare alleles have population frequency less than or equal to what?
1%
T/F some alleles are “private” to an individual, family, or population
TRUE
T/F nuclear diversity studies using SNPs were used to support RAO model
TRUE
ancestral vs derived alleles
Derived: alleles that differ from alleles shared by chimps and gorillas
ancestral: alleles shared by humans and gorillas but differ in chimps
T/F autosomal genetic diversity is greater in African populations than non-African populations
TRUE
T/F interbreeding occurs for Denisovans and Neandertals in East Asia, Western Europe, and Australia New Guinea with modern humans
FALSE. occurred until 100 kyr(100,000 years)
HWE equation? what does each letter mean?
p^2 + 2pq + q^2 = 1
p: frequency of dominant allele at locus
q: frequency of recessive allele at locus
2pq: expected frequency of heterozygotes
