Hardy-Weiberg Equilibrium Lab Report
Hardy-Weinberg Equilibrium
One of the most difficult concepts to understand about the process of evolution is how changes in the genetic composition of a population affect the phenotypic composition of a population, and how both ultimately act to allow evolution of the species. Charles Darwin’s theory of evolution emphasizes that populations, not individuals, evolve. The purpose of my experiment was to test the allele and genotype frequencies. Alleles for a gene are represented by letters of the alphabet.
The theory of Hardy-Weinberg states that an allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolution. How to use and understand the punett square. Also, they created a mathematical model which explains five assumptions of the Hardy-Weinberg theory. The theory states that there are no random mating, no mutation, no natural selection, no gene flow and large …show more content…
breeding population. The principle describes an ideal condition against which the effects of their influences can be analyzed.
The null hypothesis I tested was the default statement that you are not going to see any changes in.
When two organisms with heterozygous genotypes (Aa) mate, the recombination of their genes can be illustrated on a Punnett Square (figure 1).
Sperm
A allele
Sperm
a allele
Egg
A allele AA Aa
Egg
a allele Aa aa
Genetic combinations possible for a single gene from the mating of two heterogyous organisms.
By convention the dominant allele is always written first.
The five assumptions of the Hardy- Weinberg Theory are:
1. There are no genetic mutations occurring in the population.
2. There is no gene flow
3. There is no gene drift
4. Reproduction is random
5. There is no natural selection occurring
The original proportions of the genotypes in a population will remain constant from generation as long as the five assumptions are met.
Methods
I randomly created 4 offspring (2 for myself and 2 for my partner). Every time my offspring was (aa) it automatically died I had to mate again to replace it. I calculated the allele’s frequencies and the genotype frequencies. Afterwards, I made a table to organize all my data into the initial genotype, number of individuals, genotype frequencies and allele frequencies.
Results Before calculating the results of my experiment, I determined the expected frequencies of genotypes and alleles for the population. To do this, I used the original allelic frequencies for the population. (A=p, and the frequency of a=q). Then, I went on to calculate the expected genotypic frequencies using the Hardy-Weinberg equation p^2 + 2pq + q^2 = 1. The number of individuals expected for each genotype was calculated by multiplying 50 by the expected frequencies. I recorded my results in numerous tables.
Discussions and Conclusions In conclusion, genetic drift refers to chance, or random, changes in allele frequency of a gene pool. These changes cannot be predicted nor can organisms adapt to prevent these random changes. Examples of events that cause genetic drifts are natural disasters like fires and floods that randomly eliminate members of a population that are “in the wrong place at the wrong time.” The remaining members of a population reproduce more prolifically than they normally would and the alleles they carry will be present in the gene pool of subsequent generations at frequencies greater than those of an individual who were eliminated. Populations contain varied individuals. The differences affect their ability to successfully leave behind offspring. The differential success in reproduction was described by Darwin as natural selection. Natural selection results in alleles being passed on to the subsequent generation at frequencies disproportionate to their occurrence in the parental generation. Mutation contributes to natural selection as it gives rise to new alleles that may better adapt individuals containing them to their environment, and contribute to the adaption of the population as a whole.
Literature Cited
Members of the Biology Program Faculty. “Biodiversity & Evolution Lab Manual,”2011 Print
One of the most difficult concepts to understand about the process of evolution is how changes in the genetic composition of a population affect the phenotypic composition of a population, and how both ultimately act to allow evolution of the species. Charles Darwin’s theory of evolution emphasizes that populations, not individuals, evolve. The purpose of my experiment was to test the allele and genotype frequencies. Alleles for a gene are represented by letters of the alphabet.
The theory of Hardy-Weinberg states that an allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolution. How to use and understand the punett square. Also, they created a mathematical model which explains five assumptions of the Hardy-Weinberg theory. The theory states that there are no random mating, no mutation, no natural selection, no gene flow and large …show more content…
breeding population. The principle describes an ideal condition against which the effects of their influences can be analyzed.
The null hypothesis I tested was the default statement that you are not going to see any changes in.
When two organisms with heterozygous genotypes (Aa) mate, the recombination of their genes can be illustrated on a Punnett Square (figure 1).
Sperm
A allele
Sperm
a allele
Egg
A allele AA Aa
Egg
a allele Aa aa
Genetic combinations possible for a single gene from the mating of two heterogyous organisms.
By convention the dominant allele is always written first.
The five assumptions of the Hardy- Weinberg Theory are:
1. There are no genetic mutations occurring in the population.
2. There is no gene flow
3. There is no gene drift
4. Reproduction is random
5. There is no natural selection occurring
The original proportions of the genotypes in a population will remain constant from generation as long as the five assumptions are met.
Methods
I randomly created 4 offspring (2 for myself and 2 for my partner). Every time my offspring was (aa) it automatically died I had to mate again to replace it. I calculated the allele’s frequencies and the genotype frequencies. Afterwards, I made a table to organize all my data into the initial genotype, number of individuals, genotype frequencies and allele frequencies.
Results Before calculating the results of my experiment, I determined the expected frequencies of genotypes and alleles for the population. To do this, I used the original allelic frequencies for the population. (A=p, and the frequency of a=q). Then, I went on to calculate the expected genotypic frequencies using the Hardy-Weinberg equation p^2 + 2pq + q^2 = 1. The number of individuals expected for each genotype was calculated by multiplying 50 by the expected frequencies. I recorded my results in numerous tables.
Discussions and Conclusions In conclusion, genetic drift refers to chance, or random, changes in allele frequency of a gene pool. These changes cannot be predicted nor can organisms adapt to prevent these random changes. Examples of events that cause genetic drifts are natural disasters like fires and floods that randomly eliminate members of a population that are “in the wrong place at the wrong time.” The remaining members of a population reproduce more prolifically than they normally would and the alleles they carry will be present in the gene pool of subsequent generations at frequencies greater than those of an individual who were eliminated. Populations contain varied individuals. The differences affect their ability to successfully leave behind offspring. The differential success in reproduction was described by Darwin as natural selection. Natural selection results in alleles being passed on to the subsequent generation at frequencies disproportionate to their occurrence in the parental generation. Mutation contributes to natural selection as it gives rise to new alleles that may better adapt individuals containing them to their environment, and contribute to the adaption of the population as a whole.
Literature Cited
Members of the Biology Program Faculty. “Biodiversity & Evolution Lab Manual,”2011 Print