Population Genetics Flashcards
Mendelian population
Group of interbreeding, sexually reproducing individuals with a common set of genes
The gene pool is characterized by
Genotypic frequencies, allelic frequencies
Genotypic frequency
Proportion of a particular genotype
Frequency of an allele=
f(A)= (2(AA)+(Aa))/2N
Allelic frequency
Copies at allele/copies of all alleles at locus
Frequency with more than 2 alleles
A1= (2(A1A1)+1(A1A2)+(A1A3))/2N
Frequency of sex linked alleles
Allele 1
Female- 2*X1X1+X1X2
Male-X1Y
(WHEN ADDING FOR WHOLE POPULATION, ADD MALES AND FEMALES!)
Hardy Weinberg equilibrium assumptions
No natural selection
No mutation
No migration
Large population
Random mating
What does the hardy weinberg equilibrium predict?
Allelic frequency won’t change
Genotypic frequency stabilizes after one generation in proportions
Hardy weinberg equation
p^2+2pq+q^2
Positicve assortive mating
Like individuals mate
Negative assortive mating
Non like individuals mate
Inbreeding
Related individuals mate preferentially
Inbreeding depression
Reduced fitness due to increase in recessive traits
How do mutations create new alleles?
Making new proteins
How does migration alter gene pools?
Genes move between populations and alter allele/genotypic frequency
Differences between populations are _____ over time with migration
Reduced
The amount of change in allelic frequencies due to migration depends on
The amount of migration
The difference in allele frequency between populations
Natural selection
Organisms with alleles that let them survuce reproduce more (but can take several generations for levels to level out)
Genetic drift
Change in allelic frequencies because of sampling error (Small population size
Causes of genetic drift
Continual small population size, founder effect (few breeding adults to start), bottleneck effect (most of a population wiped out)
What is the cause of evolution?
Genetic drift
What are the effects of genetic drift?
Change in allelic frequencies within a population
Loss of genetic variation
Genetic variation between populations differing over time
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