Activity #96 Battling Beaks Challenge Question: Initial Thoughts: Prediction: Evidence: Table 1: Group Forkbird Population Data 1-Tined Forkbirds 2-Tined Forkbirds 4-Tined Forkbirds Initial 1 2 3 4 5 6 7 8 Table 2: Group Forkbird Population Data 1-Tined Forkbirds 2-Tined Forkbirds 4-Tined Forkbirds Initial 1 2 3 4 5 6 7 8 Graph: Class Forkbird Population Number of Forkbirds Key: 1-tined forkbirds = 2-tined forkbirds= 4-tined forkbirds= Generations Activity #96 Page 1 of 3
Analysis Questions: 1. Which type of Forkbird was the most successful? Explain how the class data support this conclusion. 2a. Look at your graph of the class results. Describe what happened to the number of each type of Forkbird over many generations. 1-tined. 2-tined. 4-tined. b. In the Forkbird model, mutations at reproduction were much more common that they are in real life. Imagine that the number of mutations was lowered, so that the vast majority of offspring had beaks similar to those of their parents. Predict what you think would have happened to the number of each type of Forkbird in future generations. 3. How did the Forkbird activity simulate the process of natural selection? Explain. (6 or more sentences) Include the following words in your answer: mutation, competition, variation, and reproduction. Activity #96 Page 2 of 3
4. The Forkbird that you studies are a single species. Although they look slightly different, they are part of a single interbreeding population. Imagine that a change in the food supply occurred. a. As a result of heavy rains, the major source of Forkbird food is now soft berries, like blueberries. After many, many generations, how many types of Forkbird do you think will be in the population? Explain your reasoning. b. As a result of a drought, the major source of Forkbird food is now sunflower seeds. After many, many generations, how many type of Forkbird do you think will be in the population? Explain your reasoning. Summary: In the beginning of Activity # I thought the answer to the challenge question was.. but now I think (or still think) My evidence for this is Activity #96 page 3 of 3
How Evolution Works: Breeding Bunnies In this activity, you will examine natural selection in a small population of wild rabbits. Evolution, on a genetic level, is a change in the frequency of alleles in a population over a period of time. Breeders of rabbits have long been familiar with a variety of genetic traits that affect the survivability of rabbits in the wild, as well as in breeding populations. One such trait is the trait for furless rabbits (naked bunnies). This trait was first discovered in England by W.E. Castle in 1933. The furless rabbit is rarely found in the wild because the cold English winters are a definite selective force against it. Note: In this lab, the dominant allele for normal fur is represented by F and the recessive allele for no fur is represented by f. Bunnies that inherit two F alleles or one F and one f allele have fur, while bunnies that inherit two fs have no fur. Challenge Question: How does natural selection affect allele frequency over several generations? Initial Thoughts: Prediction: (State what you would predict (if your hypothesis is true) about the frequency of F alleles and f alleles in the population of rabbits after 10 generations, where ff bunnies are selected against (do not survive)). Materials: Gene Frequency data form Discussion Questions red beans (in plastic zip bag) white beans (in plastic zip bag) paper bag 3 containers labels (we can use paper towel) Procedures: 1. Copy the Gene Frequency Data form and the Discussion Questions. Write a hypothesis and specific predictions based on that hypothesis. 2. The red beans represent the allele for fur, and the white beans represent the allele for no fur. The container represents the English countryside, where the rabbits randomly mate. 3. Label one dish FF for the homozygous dominant genotype. Label a second dish Ff for the heterozygous condition. Label the third dish ff for those rabbits with the homozygous recessive genotype. 4. Place the 50 red and 50 white beans (alleles) in the container and shake up (mate) the rabbits. (Please note that these frequencies have been chosen arbitrarily for this activity.)
5. Without looking at the beans, select two at a time, and record the results on the data form next to "Generation 1." For instance, if you draw one red and one white bean, place a mark in the chart under "Number of Ff individuals." Continue drawing pairs of beans and recording the results in your chart until all beans have been selected and sorted. Place the "rabbits" into the appropriate dish: FF, Ff, or ff. (Please note that the total number of individuals will be half the total number of beans because each rabbit requires two alleles.) 6. The ff bunnies are born furless. The cold weather kills them before they reach reproductive age, so they can't pass on their genes. Place the beans from the ff container back in the white bean zip bag before beginning the next round. 7. Count the F and f alleles (beans) that were placed in each of the "furred rabbit" dishes in the first round and record the number in the chart in the columns labeled "Number of F Alleles" and "Number of f Alleles." (This time you are really counting each bean, but don't count the alleles of the ff bunnies because they are dead.) Total the number of F alleles and f alleles for the first generation and record this number in the column labeled "Total Number of Alleles." 8. Place the alleles of the surviving rabbits (which have grown, survived and reached reproductive age) back into the container and mate them again to get the next generation. 9. Repeat steps five through nine to obtain generations two through ten. 10. If working as a team, make sure everyone in your group has a chance to either select the beans or record the results. 11. Determine the gene frequency of F and f for each generation and record them in the chart in the columns labeled "Gene Frequency F" and "Gene Frequency f." To find the gene frequency of F, divide the number of F by the total, and to find the gene frequency of f, divide the number of f by the total. Express results in decimal form. The sum of the frequency of F and f should equal one for each generation 12. Graph your frequencies. Prepare a graph with the horizontal axis as the generation and the vertical axis as the frequency in decimals. Plot all frequencies on one graph. First, plot your own data. Use a solid line for F and a dashed line for f. Then graph the other groups results. Use the same symbols for each group but a different color. Example graph Allele Frequencies across Generations Frequency 1 0.8 0.6 0.4 0.2 0 1 2 3 4 5 6 7 8 9 10 Dominant allele (F) Recessive allele (f) Generation
Evidence: 2001 WGBH Educational Foundation and Clear Blue Sky Productions, Inc. All rights reserved. Allele Frequency Changes Across Generations Graph
Analysis Questions: 1. Compare the number of alleles for the dominant characteristic with the number of alleles for the recessive characteristic. 2. Compare the frequencies of the dominant allele to the frequencies of the recessive allele. 3. In a real rabbit habitat new animals often come into the habitat (immigrate), and others leave the area (emigrate). a. How might emigration and immigration affect the gene frequency of F and f in this population of rabbits? b. How might you simulate this effect if you were to repeat this activity? 4. How do your results compare with the class data? If significantly different, why are they different? 5. How are the results of this simulation an example of evolution? Summary: In the beginning of this activity I thought the answer to the challenge question was But now I think. Questions from: 2001 WGBH Educational Foundation and Clear Blue Sky Productions, Inc. All rights reserved.
Classification, Dichotomous Keys and Evolution (Sneaker and Galapagos Reptiles lab) Challenge Questions: 1. How can a group of objects/organisms be classified using features or traits they have in common? 2. How can evolutionary relationships be revealed in this process? Initial Thoughts: Materials: Students shoes, Galapagos Reptiles class handouts, paper, pen and pencil. Procedures: 1. Remove your right shoe and place it on your table. 2. As a group, think of a characteristic that will divide all of the shoes in your group into two main categories (taxa, for example Kingdoms). 3. Place the shoes into separate piles based on the characteristic your group has selected. 4. Next, working only with the shoes in one kingdom, divide that group into two groups based on a new characteristic (two phyla). 5. Further divide these groups until each shoe is in its own grouping. 6. Repeat with the other shoe kingdom. 7. Draw a cladogram (branching tree diagram) of your shoe classification. (see example) 8. Create a dichotomous key of your shoe classification. (see example) 9. Once your group (university) has completed the Shoe classification challenge, proceed to use the Galapagos Reptiles data to create a cladogram and dichotomous key for the reptiles. 10. Make sure all members of your research group participate and work together in a respectful manner. All members of your group must have the correct information, be done with the lab write up and be able to explain your findings. The National Science Foundation (Ms. Kim) will grant the first University (group) to have accomplished this, in a published format (blue or black ink where appropriate) a grant (a HW pass) Examples: Candy bar dichotomous key Candy in our sample: Lifesaver, M&M s, Hershey s kisses, Hershey s bar, 3 Musketeers, Milky Way and Snickers. 1 a Not Chocolate..Lifesaver b Chocolate.go to step 2 2 a Not a bar..go to step 3 b Bar go to step 4 3 a Not individually wrapped M&M s b Individually wrapped.hershey s Kisses 4 a No Nougat..Hershey s Bar b Nougat.go to step 5 5 a No caramel..3 Musketeers b Caramel.go to step 6 6 a No peanuts Milky Way b Peanuts.Snickers
Evidence: Shoe Dichotomous key
Shoe Cladogram (Branching tree diagram) Galapagos Island Reptile Dichotomous key
Galapagos Islands Reptile Cladogram (Branching tree diagram) Analysis Questions: 1. Did the theory of evolution change the way biologists think about classification? Explain. 2. What information can scientists use to figure out the evolutionary history of a species? Summary: In the beginning of this activity I thought the answer to the challenge question was.. but now I think (or still think) My evidence for this is
Evolution Study Guide Darwin s Theory(7.1) Know the key terms and ideas Species, fossil, adaptation, evolution (book and class definitions), scientific theory, natural selection, variation. Be familiar with the observations that led Darwin to produce his Theory of Evolution. (diversity, remains of organisms, characteristics of Galapagos Islands organisms.) What did Darwin reason happened in the Galapagos Islands to explain the diversity, as well as the similarities and differences between the animals on the Islands versus on the mainland? What did he hypothesized happened over many generations? What are the roles of variation and environmental factors in causing natural selection? Evidence of Evolution(7.2) Know the key terms and ideas Comparative anatomy, homologous structures, mold, cast, petrified fossil, trace fossil, paleontologist, gradualism, punctuated equilibria. Know the four main lines of evidence of evolution. When do most fossils form, what is the most common way fossils form? What is the fossil record and what evidence does it provide? Evolution of Species(7.3) Know the key terms and ideas Habitat, extinct How have we arrived at the diversity we see today? (environment/genetic variation/natural selection). How do new species form? What causes extinction? What lines of evidence are used to determine relationships between species? Classifying Organisms(7.4) Know the Key terms and ideas Classification, taxonomy, binomial nomenclature, genus, prokaryote, eukaryote Why do scientists classify things, including living things? Understand that the more classification levels organisms share them more things they have in common or the more closely they are related. Know how living things are classified (domains, kingdoms, phyla, class, order, family, genus, species) and how living things are named. Branching Trees (Cladograms) (7.5) Know the Key terms and ideas Branching tree diagram, cladogram (from class), derived shared characteristic (usually these are homologous structures too). Know what a branching tree diagram shows, and how they are constructed. Know how to interpret these diagrams and be able to tell which groups are more closely related, share more common ancestors, and explain how you can tell.