25 1 Genotypic and Allelic Frequencies Are Used

  • Slides: 16
Download presentation
25. 1 Genotypic and Allelic Frequencies Are Used to Describe the Gene Pool Of

25. 1 Genotypic and Allelic Frequencies Are Used to Describe the Gene Pool Of a Population • Calculating genotypic frequencies • F = No. AA individuals/N • N: total no. of individuals • F: frequency of AA alleles. • Calculating allelic frequencies • Frquency of an allele = No. copies of the alleles/No. copies of alleles at the locus in a population.

25. 2 The Hardy-Winberg Law Describes the Effect of Reproduction on Genotypic and Allelic

25. 2 The Hardy-Winberg Law Describes the Effect of Reproduction on Genotypic and Allelic Frequencies • Hardy-Weinberg Law • Assumption: population is large, randomly mating, not affected by mutation, migration, or natural selection. • Prediction 1: the allelic frequencies of a population do not change. • Prediction 2: the genotypic frquencies stabilize.

Genotypic frequencies at H-W equilibrium • p+q=1 • p 2 + 2 pg +

Genotypic frequencies at H-W equilibrium • p+q=1 • p 2 + 2 pg + q 2 = 1 • P 2: homozygous dominant allele pair frequency. • Q 2 : homozygous recessive allele pair frequency. • 2 pq: heterozygous allele frequency.

Concept Check 1 What is the expected frequency of heterozygotes in a population with

Concept Check 1 What is the expected frequency of heterozygotes in a population with allelic frequency X and Y that is in H-W? a. b. c. d. X+Y XY 2 XY (X- Y)2

Concept Check 1 What is the expected frequency of heterozygotes in a population with

Concept Check 1 What is the expected frequency of heterozygotes in a population with allelic frequency X and Y that is in H-W? a. b. c. d. X+Y XY 2 XY (X- Y)2

25. 3 Nonrandom Mating Affects the Genotypic Frequencies of a Population • Positive assortative

25. 3 Nonrandom Mating Affects the Genotypic Frequencies of a Population • Positive assortative mating: • a tendency of like individuals to mate. • Negative assortative mating: • A tendency of unlike individuals to mate.

Inbreeding • Increases frequency of homozygotes in population • Rate is affected by how

Inbreeding • Increases frequency of homozygotes in population • Rate is affected by how closely related mating pairs are

Concept Check 2 What is the effect of outcrossing on a population? a. b.

Concept Check 2 What is the effect of outcrossing on a population? a. b. c. d. Allelic frequency changes in the population. More heterozygotes will be produced in the population. Fewer heterozygotes will be produced. It will reach the H-W equilibrium

Concept Check 2 What is the effect of outcrossing on a population? a. b.

Concept Check 2 What is the effect of outcrossing on a population? a. b. c. d. Allelic frequency changes in the population. More heterozygotes will be produced in the population. Fewer heterozygotes will be produced. It will reach the H-W equilibrium

25. 4 Several Evolutionary Forces Potentially Cause Changes in Allelic Frequencies • Mutation •

25. 4 Several Evolutionary Forces Potentially Cause Changes in Allelic Frequencies • Mutation • Migration • Genetic Drift • Founder effect • Genetic bottle neck • Natural selection

Changing Allele Frequencies Allelic Frequencies Change When ThereChanging Allele Frequencies Allelic Frequencies Change When There
1 Determine the gene and genotypic frequencies of1 Determine the gene and genotypic frequencies of
8 5 Allelic Frequencies and population genetics Learning8 5 Allelic Frequencies and population genetics Learning
Allelic Frequencies and Population Genetics 8 5 StarterAllelic Frequencies and Population Genetics 8 5 Starter
Punnett Squares Have limitations in predicting allelic frequenciesPunnett Squares Have limitations in predicting allelic frequencies
A HARDY WEINBERG PROBLEMS CALCULATING NEW ALLELIC FREQUENCIESA HARDY WEINBERG PROBLEMS CALCULATING NEW ALLELIC FREQUENCIES
Modeling Populations forces that act on allelic frequenciesModeling Populations forces that act on allelic frequencies
Population Genetics Allele Frequencies Genotype Frequencies The HardyWeinbergPopulation Genetics Allele Frequencies Genotype Frequencies The HardyWeinberg
FREQUENCIES Running the Analysis The Frequencies procedure providesFREQUENCIES Running the Analysis The Frequencies procedure provides
1 Frequencies Percents 1 FREQUENCIES Mean Median Mode1 Frequencies Percents 1 FREQUENCIES Mean Median Mode
Given genotype frequencies calculate allele frequencies in aGiven genotype frequencies calculate allele frequencies in a
Used Ep Used Esxsy Used sxsy Used EpUsed Ep Used Esxsy Used sxsy Used Ep
Used Ep Used Esxsy Used sxsy Used EpUsed Ep Used Esxsy Used sxsy Used Ep
USED TOTO BE USED TOGET USED TO UsedUSED TOTO BE USED TOGET USED TO Used
Phenotypic and genotypic impact of milk components andPhenotypic and genotypic impact of milk components and