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20 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the goals of population genetics
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1. characterize the distribution of genetic variation within and among populations
2. Changes in genetic structure over time (evolution) |
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What is the allele frequecies of
200 rr 500 Re 300 RR geonotype frequencies |
550 R
450 r gf .2 rr .5 Rr. .3 RR |
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Changes in allele/ genotypre frequencies over time area a consequence of?
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1. Natural selection
2. Gene flow 3. Mutation 4. Genetic Drift 5. Non-random mating what do these five things do? |
cause changes in allele frequencies
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Assumptions of Hardy-weinberg Equilibrium?
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1. Random Mating
2. Negligable mutation and migration 3. infinitely large population size (no genetic drift) 4. no diffferential survival or reproduction (no natural selection) 5. Mendelian inheritance |
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If assumptions of the hardy-weinberg model are met then the following will be true?
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The population WILL NOT evolve which means?
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allele frequencies will be constant from generation to generation = hw equilibrium
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Steps of testing wether a population is in HW proportions (3 steps)
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1. determine allele frequencies from observed genotype numbers under HW model
2. calculate expected genotype numbers under HW model 3. Compare oberved number to expected numbers using a chi-square test |
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AA 47
Aa 46 aa 7 allele frequencies |
A 140/200 = .7
a 60/120 = .3 does p2 +q2 +2pq = 1 what are expected genotypes |
no
AA = 49 Aa = 42 aa = 9 |
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Chi squared test
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Sum of (observed - expected)2 / expected
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What is definition of genetic drift
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changes in allele frequency due to random sampling from generation to generation
Genetic drift _____ genetic variation within populations but ____ variation between populations |
eliminates
increases |
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Point of gumballs Random _____ skews the frequency distribution relative to ______
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subsampling
relative to original source frequency (bigger sample size = more accurate |
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A relatively ______ subsample of any population contributes ______
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small
to next generation Genetic drift (random sampling) occurs _____ in different ______ |
independently
isolated populations |
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THe initital frequency of a ____ mutation (allele) = ____
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new mutation
1/2 N The probability that a new mutation (allele) will eventuall become ____ = its ____ in the popujlation |
fixed = frequency
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Over time all loci will become fixed for one allele. Therefor both ______ and _____ go to zero
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heterozygosity and polymorphism
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What is a consensus population size of Nsubc:
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total number of individuals in a populations
What is Effective population size Nsube |
= the number of individuals in a population that can contriubte to the next generation (reproduce and have offspring)
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Nsub e is strong correlated to
3 things |
1. rate of genetic drift (random loss of genetic variation)
2. Risk of inbreeding 3. maintenance of genetic variation in a population over time |
genetic variation is typically maintained or increases in large populations
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when sex rations are not equal. Nsube is strongly influenced by the rarer of the two sexes
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Nf Nm Ne
1000 1 4 1000 2 8 1000 3 12 1000 4 15.9 Ne is a special concern among _____ species |
POLYGAMOUS
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the effective population size Ne is generall only ____ of the effect population size (N)
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10%
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estimating Ne of ancesteral population often requires ____ rate of the marker used to be known
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mutation
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Loss of genetic variation due to a bottleneck effect depends on (3 things)
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1. the magnitude of Ne reduction
2. duration (the number of generations at small Ne 3. the rate if population decline |
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in FSt 0 means and 1 means
Fis 0 and 1 |
0 no population structure
1 fully sperate populations 0 is no inbreeding 1 is full inbreeding |
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