Hardy Weinberg Lab Report

Hardy Weinberg Lab Report Recessive Allele Survivability AP Biology, Mod 19 Abstract. The theory of recessive allele survivability and its relation to hairless rabbits was examined by using the Hardy Weinberg Model. The survivability of recessive alleles was examined by selecting red and white beads from a bowl to symbolize recessive and dominant alleles - the recessive being white and the dominant being red. The recessive alleles slowly dwindled down to four alleles in the tenth generation, from the original 50, symbolizing the death of the hairless rabbits due to the cold weather. No preference for tree circumference was noted. These data suggest that beaver food choice concurs with the optimal foraging theory. Introduction In this lab, we explore the diminishing presence of recessive alleles, specifically that within hairless rabbits vs. haired rabbits. It is suspected that, through natural selection, the recessive alleles that cause an inhibition on an organism will cause those organisms to die off - making the presence of that recessive alleles less likely to be in the next generation of organisms. In the case of the hairless rabbits, they would die off in the colder months, and the haired rabbits would survive to pass on their genes. The significance of the survivability of recessive alleles is important for the theory of evolution and natural selection. The extinction of millions of different species has aided in the process of evolution for other organisms. Without the disappearing of recessive alleles, it would be very difficult to survive for the organism carrying them. They would have many disadvantages.        The main objective of this lab was to see the process of natural selection taking its course in nature, specifically in hairless rabbits. They make a good example, because they die off more quickly due to the harsh winters of England. This proves that survival of the fittest does take place.        We hypothesized that, through the generations, the hairless rabbits would die off, and the dominant alleled rabbits would soon become the only rabbits to live. We believed this to be true, because - given time - every combination possible will take place, and all of the white rabbits would end up dying. Of course, with only ten generations to work with, some did survive, because not all combinations took place. Methods To show the genes being passed down generation to generation, we used beads to represent the bunnies and the offspring. We used the red beads as ‘F’(dominant) and the white as ‘f’(recessive), we dumped 50 of each into a bowl and picked 2 beads without looking. The two beads we picked out would determine the genes for the offspring. We did this until there were no more beads in the bowl and recorded our results on a table that had 3 columns for each outcome. We would keep the ‘ff’ pairs out of the bowl and repeat the process until we had no more ‘f’ alleles in the bowl, or until we had repeated the lab 10 times (reaching the end of the chart). Eventually, the ‘F’ alleles would be the only beads in the bowl, or the recessive gene would stay in due to chance. Results In the experiment we found, similar to what we predicted, the FF rabbits grew in number, and the ff decreased. Because we were not given infinite amount of time, there were still some ff alleled rabbits that survied: about 2. As shown in the graph, however, there is a clear positive curve for the FF alleled rabbits. The ff alleled rabbits saw a negative curve, which we also predicted. For the Ff alleles, we also saw a negative curve. This makes sense, but we did not predict it in our hypothesis, because it was not an outcome we took into account. Of course, if the white beads would slowly be taken out, then any combination of white beads would diminish - double or alternating between white and red. Discussion The Hardy-weinberg formula allows scientists to determine whether evolution has occurred. Any changes in the gene frequencies in the population over time can be detected. The law essentially states that if no evolution is occurring, then an equilibrium of allele frequencies will remain in effect in each succeeding generation of sexually reproducing individuals. In order for equilibrium to remain in effect, then no mutations, gene flow, or selection can occur. Random mating must occur and the population must be big enough so that no genetic drift can cause the allele frequencies to change. The result of this lab was that as each furless rabbit died off in the previous generation, there would be a decrease in the amount of furless rabbits in the next generation. This is because as the alleles die off, in one generation, it becomes less likely for them to be present in the next generation. Eventually, there will be no more recessive pairs of alleles, as seen in the 10th generation of this lab. The probability of the recessive allele pairs surviving got slimmer through each generation. This lab gave us the opportunity to observe how a specific recessive allele pairs become less likely to appear in an environment that does not suit them. Although some of the hairless rabbits survived through the generations, eventually all the furless rabbits did not survive anymore. Conclusion The purpose of this lab was to learn about the recessive allele survivability  by using red and white beads for hairless rabbit survivability. We now know that the Hardy Weinberg model  allows us to predict the survival rate of hairless rabbits in England. We were able to observe and record survival of the fittest in the lab as the bunnies with the recessive genes couldn’t withstand the environment while the bunnies with two dominant genes or a dominant and recessive continued to live.