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WEEK 7 EXPERIMENT Evolutionary Change without Natural Selection

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Question;WEEK 7 EXPERIMENT ANSWER SHEETPlease submit to the;Week 7 Experiment dropbox no later than Sunday midnight.;SUMMARY OF ACTIVITIES FOR WEEK 7 EXPERIMENT ASSIGNMENT;Experiment 7 Exercise 1 ? Evolutionary Change without;Natural Selection;Experiment 7 Exercise 2 ? Evolutionary Change;with Natural Selection;Experiment 7 Exercise 3 ? Evolution and Genetic;Drift;Before;starting, be sure you have read over the information in the Week 7 Experiment Introduction.;Materials Needed;For the;first two exercises you will need the following;50 red M&Ms and 50 green M&Ms or 50 each of two items that are;distinguishable by color but are similar in size and texture (e.g., dimes;and pennies, two different color beads).;Four containers large enough to hold;the above items.;Experiment 7 Exercise 1: Evolutionary Change without Natural Selection;In this;first exercise, we are going to look for evidence of evolutionary change in a;population in the absence of natural;selection by looking at the change in allele frequencies over time in a;simulated population. We will start with a population of 50 individuals in which there are two alternate alleles (H;and h);in equal proportions (each at a frequency of 0.5 or 50%). Individuals have the;possible genotypes: HH;Hhor hh.;These two alleles do not;offer any selective advantage, so neither is selected for or against, meaning;they are neutral. We will record the;frequency of these alleles over 10 generations. Prior to advancing on to the;next generation, six alleles (= three individuals) will be removed at random.;Before you begin;answer the following;Question;What is your prediction;as to what will happen to the frequencies;(note that this is different than the number) of these two alleles over 10;generations? Word your prediction as an ?if-then? statement based on the experiment design. (1 pts).;Procedure;Let 50;M&M's of one color (i.e. red) represent the dominant allele (H);and 50 M&M's of another color (i.e. green) represent the recessive allele (h).;Let one container represent the Habitat where random mating occurs.;Place all of the M&Ms (or other items) into this container. This is;your starting gene pool of your;?parent? population or Generation 0.;Label the other three containersHHfor;homozygous dominant individuals, Hh for heterozygous individuals;and hh for the homozygous recessive individuals. Notice that;individuals have two alleles.;Mix up your Habitat;well and without looking, select two;items (alleles) at a time, these two alleles represent a single individual. On a piece of paper, keep track of the genotypes of the individuals;withdrawn. For instance, if you draw one red and one green M&M, that;counts towards "Number ofHhindividuals." If you draw two;red M&Ms, that counts towards "Number ofHHindividuals" and so on.;Continue drawing pairs and recording the results;until all items (alleles) have been withdrawn and sorted. Be sure to place;the ?offspring? into the appropriate dish:HH, Hh, or hh. Note that the total number of;individuals will be half the total number of items because each individual;requires two alleles, so you will have 50 offspring (but 100 alleles). Record the number;of HH, Hhand hh individuals drawn for Generation 1 in Table 1 below.;Next count (or calculate) the total number of H and the total number of h;alleles for the first generation and record the number in Table 1 below in the columns;labeled "Number of H;Alleles" and "Number of h;Alleles.;Add up the total number ofHalleles andhalleles for the first;generation and record this number in the column labeled "Total Number;of Alleles." If you did everything correct, you should still;have 50 H alleles and 50 h alleles.This has;already been entered for you in the Table below for Generation 1.;Combine the HH;Hhand hh individuals back into the Habitat container and mix well. Randomly remove three;pairs of alleles (= three individuals, six items) and set them aside.;Repeat steps D through H to obtain Generations 2;through 10. Remember to randomly remove threepairs of alleles each time.Because I know that each;generation will have six fewer;alleles, I have also entered the total number of alleles in the Table;below. Be sure that is the number your alleles add up;to!;Here is a photograph of;this process after six generations. The sixth generation has been distributed;into the HH, Hh and hh containers.;Note that dimes and pennies have been used.;After entering your number of individuals and;allele counts for each generation, you now need to determine the allele frequencyofHandhfor each generation and record them;the Table below. To determine;allele frequency take;# ofH/Total alleles in the generation;= Allele frequency ofH(express as a decimal);# ofh/Total alleles in the generation;=Allelefrequency ofh;Note that the total number of alleles will change each;generation, but the frequency the H;allele plus the frequency of the h;allele should add up to 1.0 for each generation.;Table 1.;Results evolutionary change without;natural selection (2 pts).;Generation;Number of HH individuals;Number;of Hh individuals;Number;of hh individuals;Number;of H alleles;Number;of h alleles;Total;Number of alleles;Allele;Frequency of H;Allele;Frequency of h;1;50;50;100;0.5;0.5;2;94;3;88;4;82;5;76;6;70;7;64;8;58;9;52;10;46;Generate a line;graph of Allele frequency vs Generation. This means you need to graph;the last two columns of your data in the Table above. Paste your graph;below. Be sure to label your axes (3 pts).;Questions;Describe what your graph above depicts with;respect to the frequency of the two different alleles across generations(2 pts).;Was your prediction correct? Why or why not (1 pts)?;Define evolution. Are the;results of this simulation an example of evolution? Explain your answer. Cite any sources used (4 pts).;Experiment 7 Exercise 2: Evolution Change with Natural Selection;In this;second exercise, we will determine the effect that natural selection has on the frequency of two alleles which start;off in equal proportions (50:50) in the population. This time, individuals who;are hh die, meaning the homozygous recessive allele combination is lethal. These individuals will be;removed from the gene pool when they are drawn and will not contribute to the;following generation. This means that the h;allele is being selected against. Keep in mind that carriers of this lethal allele (e.g., those individuals that are Hh) are unaffected because the h allele is recessive.;Question;1.;What;is your prediction as to what will;happen to the frequencies of these two alleles over 10 generations? Word your;prediction as an ?if-then? statement based on the experimental design. (1 pts).;Procedure;A.;Return;ALL alleles to the Habitat container;and ensure that it contains 50 H;alleles and 50 h alleles. This is our;Generation 0.;B.;Use;the other three containers labeledHHfor homozygous dominant individuals, Hh;for heterozygous individuals and hh for the homozygous recessive;individuals.;C.;Mix;up your Habitat container well and;without looking, select two alleles;at a time, these two represent a single;individual. On a piece of paper, keep track of the type of individual withdrawn (HH, Hh;or hh).;D.;Continue;drawing pairs and recording the results until all alleles have been withdrawn;and sorted. Be sure to place the ?offspring? into the appropriate dish:HH, Hh, or hh. Record the number of HH, Hh;and hh individuals drawn for Generation;1 in Table 2 below.;E.;Next;count (or calculate) the total;number of H and h alleles for the first generation and record the number in the;Table below.;F.;Add;up the number ofHalleles andhalleles;for the first generation and record this number in the column labeled;Total Number of Alleles." If you did everything correct, you;should still have 50 H alleles and 50 h alleles.This has already been entered for you in the;Table below for Generation 1.You;will need to enter this information for Generations 2-10, as it will change.;G.;Now;it is time for natural selection.;Remove all of the h alleles from the container labeled hh and discard them. These;individuals have died and cannot reproduce.;H.;Return;the alleles of the remaining HH and Hhindividuals back to the Habitat container.;I.;Repeat;steps D through H to obtain Generations 2 through 10. Remember that each time;all hh;individuals die and are removed after you have counted them.;J.;After;entering your number of individuals and allele counts for each generation, you;now need to determine the allele;frequency ofHandhfor each generation and record them in;Table 2below.;Table;2. Results from;evolutionary change with natural selection (2 pts).;Generation;Number of HH individuals;Number;of Hh individuals;Number;of hh individuals;Number;of H alleles;Number;of h alleles;Total;Number of alleles;Allele;Frequency of H;Allele;Frequency of h;1;50;50;100;0.5;0.5;2;3;4;5;6;7;8;9;10;K. Generate a line graph of Allele frequency vs Generation #. This;means you need to graph the last two columns of your data in the Table above.;Paste your graph below. Be sure to label your axes (3 pts).;Questions;2. Describe what your graph above depicts with;respect to the frequency of the two different alleles across generations(2 pts).;3. Was your prediction correct?;Why or why not (1 pts)?;4.;Explain;why the h allele was not entirely;eliminated from the population (2 pts).;Based on;your earlier definition of evolution, are the results of this simulation;an example of evolution? Explain your answer (2 pts).;Experiment 7 Exercise 3: Mechanisms of Evolutionary Change;Be sure that;you have completed the suggested readings, your success on this exercise is;dependent on your understanding of evolutionary concepts!;Procedure;Open the following website;BioMan Biology. No date. Biology Games and;Virtual Labs: Evolutionhttp://biomanbio.com/GamesandLabs/EvoClassGames/aaevo.html;Click where it says Press Spacebar or Click Here to Continue! And click again to;continue.;Read over the instructions carefully, paying;particular attention to the controls. Notice that as you successfully;shoot the correct answer, you will need to reload.;Click again where it says Press Spacebar or Click Here to Continue!;Click on;Mechanisms and begin.;A statement will be shown at the bottom of the;screen.;Use the arrow keys to move to the correct term;and use the space to shoot it down. Remember to reload!;Keep playing until you are told ?You have succeeded here earthling! But;can you save the rest of your planet?? Start over if you fail.;Record your %;correct and score in Table 3 below when you are done.;Feel free to repeat to improve;your score if you would like.;Reload the page to start over or click;on the link above to return to the start page.;Click where it says Press Spacebar or Click Here to Continue! And click again to;continue.;Review the instructions and click again where it;says Press Spacebar or Click Here;to Continue!;Click on;Mechanisms 2 and begin.;As before, a statement will be shown at the;bottom of the screen.;Use the arrow keys to move to the correct term;and use the space to shoot it down. Remember to reload!;Keep playing until you are told ?You have succeeded here earthling! But;can you save the rest of your planet?? Start over if you fail.;Record your %;correct and score in Table 3 below when you are done.;Feel free to repeat to improve;your score if you would like.;Answer the questions;that follow.;Table 3. Results (2 pts);% Correct;Score;Mechanisms;100;1003;Mechanisms 2;100;1006;Questions;1.;Match;the following statements with the correct term (5 pts);a. Mutation f.;Bottleneck;b. Genetic drift g.;Founder effect;c. Gene flow h.;Immigration;d. Natural selection i. Emigration;e. Non-random mating j.;Speciation;Type;of genetic drift that occurs when a new colony is established, that by chance;is genetically different than the original population.;Can result in evolution by acting on;favorable traits.;Only male lions with large, thick manes are;able to breed.;Reproductive isolation of two populations;of penguins can result in this.;The loss or gain of alleles from a;population by the movement of individuals into or out of the population.;Movement;of individuals into a population, bringing with them new alleles.;Random;events that cause changes in gene frequencies.;Type;of genetic drift in which there is a drastic reduction in population size and a;change in allele frequencies.;The ultimate source of new alleles and;traits that natural selection can act on.;When individuals leave a population, taking;alleles along with them.;Week 7 Experiment Grading Rubric;Component;Expectation;Points;Experiment 7 Exercise 1;Collection of data and generation of a line graph correctly;labeled (Table 1 and graph of data).;5 pts;Demonstrates an understanding of evolutionary change without;natural selection (Questions 1-4).;8 pts;Experiment 7 Exercise 2;Collection of data and generation of a line graph correctly;labeled (Table 2 and graph of data).;5 pts;Demonstrates an understanding of evolutionary change with;natural selection (Questions 1-5).;8 pts;Experiment 7 Exercise 3;Success at Angry Aliens and an understanding;of the mechanisms of evolutionary change (Table 3).;2 pts;Demonstrates an understanding of the;various mechanisms of evolutionary change(Question 1).;5 pts;TOTAL;33;pts

 

Paper#62626 | Written in 18-Jul-2015

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