By using the group's data, I need to find the two tailed p-value from total range of 25 and 10. I need to find the sample size, means, t-statistic, and p-value of largest shift of the 25 and 10 I need to make a graph of the change in frequency of allele Ag over 5 generations for the two different population sizes (25 and 10) using the group's data. Generation (1-5) should be on the X-axis and Ay allele frequency on the Y-axis. I need to answer questions below number 1 - 6.

Simulating Genetic Drift Learning objectives: 1. Explain the role of population size in genetic drift. 2. Understand the difference between the evolutionary results of natural selection and genetic drift. 3. Further develop your skills in building and interpreting graphical data. Background: This week we will be simulating another important mechanism of microevolution, genetic drift. Genetic drift causes changes in allele frequencies of populations thrOugh time as a result of random chance. By chance, some alleles are passed on to more offspring and some are passed on to fewer offspring. This random chance affects alleles regardless of whether they are beneficial, harmful, or neutral. In Our simulation, the alleles will be neutral, so that we can see the effects of genetic drift most clearly. For these simulations y0u will be working in y0urgr0ups, but will write up the exercise individually. You will use data from the entire class (all groups) to answer some of the questions, so be sure to write your grOup's data on the board, and also to write down the other grOups' data. Begin this session by conferring with y0ur gr0up mates and agreeing upon what 'genetic drift' means and what yOu expect from an exercise that models the effects of 'genetic drift' acting alone on a population. Record your answer and include it in your post lab write-up. u. Part 1: Genetic Drift in a Population of E individuals Each group will have one container for their population's gene pool. You will be simulating genetic drift at a single locus with two alleles. Your population consists of 25 diploid individuals, so you will have 50 alleles in your gene pool. Alleles are represented by plastic beads of two different colors, one color for each allele. Assign alleles by identifying the color that corresponds to each allele, Ag or Ay, and record below. Begin your simulation with your two alleles at equal frequency (0.5 for each, that is 25/50). Count out 25 of each of your colors of beads and add them to your container. Allele 1 (Ag) = 25 (enter green) Allele 2 (Ay) = 25 (enter yellow) Your goal is to observe how much the frequencies of these two alleles change over the course of five generations, in the absence of any other evolutionary processes. In other words, this simulation will not include selection, mutation, gene flow or non-random mating. The changes will be due to random chance. You must also keep the population size (and number of alleles in your gene pool) constant from one generation to the next. 1) Sample from your gene pool: Without looking, have one member of your group select two beads, these beads represent the genotype of one offspring. Record the genotype of this individual in Table 1 (below) in the row for generation 2 (you can use hash marks to record the genotype) and return the beads to the gene pool. Repeat this process 24 more times, until you have recorded the genotypes for 25 members of the next generation. 2) Adiust allele frequencies in your gene pool: Remove the original beads from your yogurt container. Based on the genotypes of the 25 offspring you drew, calculate the proportion of alleles in the next generation, and return that proportion to the yogurt container. For example, you would add 2 green alleles to the yogurt container for every time you drew 2 green beads out of the gene pool, 1 green and 1 yellow al|e|e for every time you drew 1 green and 1 yellow bead out of the gene pool and 2 yellow alleles for every time you drew 2 yellow beads. You should wind up with 50 beads in your container. One of your two alleles probably increased in frequency, so you will need to add some of the extra beads from your initial supply. You have now assembled the second generation. 3) Calculate the allele frequencies for your generation. You will use these allele frequencies as the starting frequencies for the next generation in Table 1. The frequency of the Ag allele (green) will be equal to: number of A individuals X 2 + the number of individuals 50 Similarly, the frequency of the Ay a|le|e (yellow) will be: number ofA individuals X2 + the number ofA individuals 50 4) Sample your next generation: Starting with the allele frequencies from the previous generation, sample your next generation in the same manner that you did your first generation, drawing out two beads at a time, recording the genotype and then returning those two beads to the gene pool. 5) Repeat these steps until you have simulated 5 generations total, being sure to record your data in Table 1 as you go. _ Change in Ag Changein Ay homozygous heterozygous homozygous freq. from freq. from individuals individuals individuals previous previous 1111111 1111111 111 Total: 1 1111111 1111111 111 Total: 1 1111111 1111111 Total: 1 1111111 1111111 1111 1111 Total: 11 Total: 11 Table. 1. Changes in allele frequencies due to random draws from a population of 25 individuals. 5) Calculate total range: Once you have completed the five generations in the table above, calculate the total range of the Ag allele. To do this, subtract the lowest frequency reached during these five generations from the highest frequency reached. You should get the same answer if you do this for the Ay allele, since it shifts by the same amount as the Ag allele, but in the opposite direction. Report this value in the \"total rangezs\" column on the board. Total range 0.32 6) Find the largest allelic shift in a single generation: Now find the largest change in allele frequencies in a single generation. Look in the columns in your table, above, for the largest values in the last two columns. Report this value on the board in the \"largest Shift25\" column. The largest shift 0.14 Part 2: Genetic Drift in a Population of Q individuals 1) Now repeat the steps above, but for a population of 10 individuals. This means there will be just 20 beads in your gene pool. Initially there will be 10 of each color. Draw beads out of the yogurt container 2 at a time, record the genotype in the table below and then return the beads to the yogurt container. Do this just1o times (total), so that your population will stay at size 10. 2) Calculate the allele frequencies for each generation: The frequency of the Ag allele (green) will now be equal to: number of A individuals X 2 + the number of individuals 20 And the frequency of the Ay allele (yellow) will be: MathType number ofA individuals X2 + the number ofA individuals 20 3) Adjust allele frequencies in your gene pool: As in part 1, adjust the number of beads of each color to reflect the frequencies of these alleles in the randomly selected offspring. Repeat these steps until you have 5 generations of genetic drift for a population size of 10. Change in Ag Changeing homozygous heterozygous homozygous from from individuals individuals individuals previous previous 4 111111 Total. 6 5 11111 Totaks Table 2. Changes in allele frequencies for a population of 10 individuals. 3) Calculate total range: Calculate the total range of the frequency of the Ag allele. Report this value in thejtotal rangem\" column on the board. Total range 0.6 4) Find the largest allelic shift in a single generation: Find the largest change in allele frequencies in a single generation. Report this value on the board in the \"largest shiftm\" column. Largest shift 0.2 5) Record the values from the other groups. This is the end of the group portion of this activity. Total Range Total Range Largest Shift Name of 25 Shift of 25 of 10 of 10 1 Best 2 _ Osmosis 0.32 0.24 0.15 Ninjas Iguanas 4 Green 5 _ Wis 0.32 0.14 0.20 as Biologists TBm I i l3 ' o 16 o 25 o 20 9 Team Name 10 Bio Lab Simulating Genetic Drift: Post-lab Questions (as individuals) Part 3: Using a t-test to understand the class' data We would like to use the entire mdata to try to answer the question of whether the total range in frequencies of the Ag allele are generally larger in a population of 10 individuals or a population of 25 individuals. An obvious first step is to calculate an average total range in frequencies the populations of 25 individuals. We can see which of the average total ranges is larger. One shortcoming of comparing the averages, however, is that it is unlikely the averages would be FEQEEIXEDFEWJFJ even if there were no consistent difference between populations of 10 and populations of 25. We are looking at data about a random process, and different groups got different values even when they were simulating the same population size. Therefore, it is not same, we would like to show that the difference between these averages is large relative to variability (randomness) in our data. This would suggest that the difference between our averages represents a consistent and biologically meaningful difference in terms of how genetic drift operates on these two sizes of populations. To do this, we are going to perform a statistical test called a t-test, or Student's t-test. A t-test calculates a value, called t, which is equal to the difference between the means of two groups weighted by the variability in the data set. This tells us how large the difference is between our two groups, relative to the background noise in our data. The t-test will allow us to sort between two possibilities. b- One possibility, called the null hypothesis, is that there is no difference at all between populations of size 10 and populations of size 25, and the only reason the averages of these two groups are not identical is random chance (Lithe backgrOund noise). 33- The other possibility, called the alternative hypothesis, is that populations of size 10 and size 25 differ in terms of how genetic drift operates and therefore have consistently different total ranges in the frequency of the Ag allele. We will use our t value to look up the probability of the null hypothesis being true. The statistical test uses our data to calculate a value called 't\". High values of t indicate that the difference between two groups is unlikely to be due to chance while small values of t indicate that the difference could easily be explained by random chance. The t statistic can be used to find the exact probability that a difference as large as we observe could be due to chance. This probability is called our p value. As a probability, it ranges from 0 to 1. If our p value is less than 0.05, this means there is less than a 5% chance that our null hypothesis is true given how different our averages look. If there is less than a 5% chance that there is no difference between populations of size 10 and size 25, we will consider this possibility unlikely, and will conclude that genetic drift operates differently in populations of size 10 and 25. To find our t statistic and p value you will enter the Wdata into a free online statistical tool calledmggts; httpzl{www.vassarstats.net{tu.html Follow the directions on the Wttest page. Under \"Setup\| Finally, answer the following Questions: 1) Looking only at your group's data, how did the allele frequencies change in the population of 10 individuals and the population of 25 individuals? Did one or the other population seem to change more rapidly in terms of its allele frequencies? 2) Prior to the simulation, which of these populations would you expect to see larger single generation shifts in allele frequencies in? Why? Did the class _a_s_a_wh_ql_e _s_e_e_ larger single generation shifts in allele frequencies in the population of 10 individuals or the population of 25 individuals? Use the averages for population size 10 and 25, as well as your p-value to answer this question. Did you reject your null hypothesis in this case? individuals or the population of 25 individuals? How does this compare to the single generation shifts in allele frequencies in terms of the difference between the population of 10 individuals and 25 individuals? Use the averages for population size 10 and 25, as well as your pvalue to answer this question. Did you reject your null hypothesis in this case? 4) How do you think the population sizes in this exercise (10 and 25 individuals) Mm real life populations? How might this affect the total range of allele frequencies seen in five generations, as well as the magnitude of single generation shifts in allele frequencies? 5) Initially, I was planning to have you conduct this simulation using the beans that you used for the natural selection simulations. However, when testing the simulations, I found that I was biased in terms of which beans I would draw from the container. When using black-eyed peas and black beans, for example, I would preferentially draw black-eyed peas, presumably because of their shape or feel. What microevolutionary process (other than genetic drift) was I inadvertently simulating? If you were to incorporate this process into your simulation, using beads, how might you do so? Be sure to explain why you think your new simulation incorporates this evolutionary process. 6) This lab simulates genetic drift over a short time scale. Over mscales (e.g. >1ooo generations) does genetic drift increase or decrease genetic variability within populations