Abstract
Hardy-Weinberg explored the genetic variation in a population using five principles: no genetic drift, a closed population, absence of mutations, random mating patterns, and the lack of natural selection. It is called the Hardy-Weinberg Equilibrium (HWE); its goal is for the genetic variation to remain persistent from one generation to the next.
The investigation aimed to figure out whether the East Carolina University’s (ECU) Brassica rapa complied with HWE after leaving the (RCBr) alone for two days, and what it resulted after these operations. It was required to collect the data related to the number of plants that had to become purple – dominants or green – homozygotes. Considering the gained information, the hypothesis is: if a population is not HWE, more forces are involved in its species. The completed experiment determined that the examined Brassica rapa was not equilibrium as it did not meet all of the principles of Hardy-Weinberg’s model.
Hardy Weinberg Equilibrium: The Brassica Rapa Examination
The experiment’s goal was to answer the question of whether the ECU population of Brassica rapa was in Hardy-Weinberg equilibrium. To achieve it, the RCBr plant, also known as the Wisconsin fast plant, was used due to its specific purple stem phenotype. Abramovs et al. (2020) state that “according to HWE, for a locus with alleles A and a with frequencies p and q, possible genotypes possible: AA, Aa, and aa with expected frequencies p2, 2pq, q2” (p. 210). These scientific observations were applied to get evidence-based results of the experiment.
The anthocyanin reaction was chosen to detect the alleles for the RCBr plant. Anthocyanin is a water-soluble vacuolar pigment that includes colors such as blue, violet, or red flavonoid, which can be found in plants (Khoo et al., 2017). Its pathway is altered by changes that can result in green stems without purple color. It indicates that purple is dominant, and green is the recessive allele since it correlates with the mutation. Therefore, possible alleles would be homozygous AA, heterozygotes Aa, and homozygotes aa.
The examination results predict that the RCBr plant is not in Hardy-Weinberg equilibrium due to one or more forces acting in the population. These forces include mutation, natural selection, nonrandom mating, genetic drift, and gene flow. Although the experiment did not include the examination of factors making the population not equilibrium, there was a possibility that forces like nonrandom mating and mutation affected the RCBr plant’s genes.
Materials and Method
Materials needed for this experiment were: a pipette, plant DNA extraction, miniature tubes to put the leaf in, a heater, a freezer, and gel for electrophoresis. At first, a small piece of leaf was broken down into miniature tubes to collect the DNA from these specific parts. Then, the mini-pipe was placed on the heater and stored there for ten minutes. Finally, the item was extracted and put in the well of the gel electrophoresis for two days. The goal was to determine if each of the small rectangles in the gel electrophoresis were heterozygous or homozygous.
Results
The table above contains the evidence counting received during the experiment. The allelic frequencies were calculated using the Hardy-Weinberg formulas p=p2 + ½(2pq) and q=q2 + ½(2pq) with p2 representing the homozygous dominant genotype (AA), 2pq representing the heterozygous genotype (Aa), and q2 representing the homozygous recessive genotype (aa). The experiment concludes that the ECU population of Brassica rapa is not Hardy-Weinberg equilibrium.
Discussion
Data collection and analysis disclosures that the ECU population of Brassica rapa is not Hardy-Weinberg equilibrium. The reason is that the expected genotypic frequencies and the observed genotype frequencies did not match up. While the expected frequency for homozygous dominant genotype (AA) was 0,405, the practical number was 0,4545. Thus, there are more than one of the principles involved: mutation, natural selection, nonrandom mating, genetic drift, or gene flow. There might be alternate explanations to the given results, and each group’s data can be different or depend on the numbers received.
Moreover, it might be possible that the other factor influences the population in equilibrium. The Hardy-Weinberg equilibrium tests are widely used as it is a vital section for many population genotypes analyses (Hao & Storey, 2019). All of the experiments related to the test can provide scientists with comprehensive data for further genetic elaboration.
References
Abramovs, N., Brass, A., & Tassabehji, M. (2020). Hardy-Weinberg Equilibrium in the Large Scale Genomic Sequencing Era.Frontiers in Genetics, 11, 210. Web.
Hao, W., & Storey, J. D. (2019). Extending tests of Hardy–Weinberg equilibrium to structured populations.Genetics, 213(3), 759-770. Web.
Khoo, H. E., Azlan, A., Tang, S. T., & Lim, S. M. (2017). Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits.Food & Nutrition Research, 61(1), 1361779. Web.