The Flashy Guppy Data Analysis PDF - 2021 College Board

Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution The Flashy Guppy Data Analysis...

Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution The Flashy Guppy Data Analysis PERFORMANCE TASK Read the following information, then complete Parts 1 and 2. INTRODUCTION: THE FLASHY GUPPY A properly dressed male guppy, with its bright blue spots and brilliant splashes of orange, can’t help but stand out. But for a fish that spends its life swimming among predators, it seems that good camouflage would have a big advantage over colors that attract attention. If flashiness is a liability, why do we still see this trait in the population? ENDLER’S RESEARCH When evolutionary biologist John Endler began studying Trinidad’s wild guppies in the 1970s, he was struck by the wide variation among guppies from different streams, even among guppies living in different parts of the same stream. Males from one pool sported vivid blue and orange splotches along their sides, while those farther downstream carried only modest dots of color near their tails. Endler also observed differences in the distribution of guppy predators, and in the color and size of gravel in different stream locations. Endler photographed hundreds of guppies and carefully collected data about their size, color, and the size and placement of their spots. He began to see a strong correlation between where guppies lived in a particular stream and whether the fish were bright or drab. But what was responsible for these trends in coloration? And if bright colors made guppies more conspicuous to predators, why should males be colorful at all? To find out, Endler formed a hypothesis based on his observations, and then set out to test it. His results proved to be one of evolutionary biology’s most important discoveries. GUPPY HABITAT TYPES Guppies usually occupy the entire length of Trinidad’s Aripo River, and often so do their predators, such as pike cichlids, blue acara, and rivulus. However, different sections of the river offer unique environmental characteristics and pressures that may influence the color variation seen in the guppies (see the table on the next page). Teacher Resource 243 Pre-AP Biology © 2021 College Board BIO_U2_TR.indd 243 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution PERFORMANCE RIVER SECTION POPULATIONS TASK Deep Pool Pool Behind Natural Dam Shallow Pool Description Deep section Pool formed by a low- Shallow area along along the lying rock dam; the dam the waterway, where waterway limits upstream movement only small fish can of some of the largest live predators Population ƒ Guppies ƒ Guppies ƒ Guppies ƒ A variety of ƒ Some predators (no ƒ Smallest and predators large ones) least effective predators Predation High Moderate Low Risk SPECIES INFORMATION Guppies collected during the experiment were classified into four color variants: brightest, bright, drab, and drabbest. Endler was interested in studying whether the pressures for mating and predation influenced the frequency of the color variations found in different populations along the river. The table shown provides information about the guppies Endler studied and their predators. PREDATORS AND PREY IN ENDLER’S STUDY Description Images Common name: Pike cichlid Scientific name: Crenicichla alta Size: Up to 12 in. (approximately 30 cm) Common name: Blue acara Scientific name: Aequidens pulcher Predators Size: Up to 7 in. (approximately 18 cm) Common name: Rivulus Scientific name: Rivulus hartii Size: Up to 5 in. (approximately 12.5 cm) Pre-AP Biology 244 Teacher Resource © 2021 College Board BIO_U2_TR.indd 244 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution PERFORMANCE Common name: Guppy or millions fish TASK Scientific name: Poecilia reticulata Brightest Sex of individuals in study: Male Size: 1.4 in. (approximately 3.5 cm) Prey Color variations in population: Brightest Drabbest Bright Drab ƒ Drabbest Text and data above are excerpted and adapted from “Sex and the Single Guppy.” © 2010 by PBS. http:// www.pbs.org/wgbh/evolution/sex/guppy/low_bandwidth.html. PART 1: ANALYZING DATA The data sets shown are representative of findings from Endler’s research. Examine the data and complete the tables and graphs. Experimental Site 1 Information River Site: Deep pool Number and Type of Predators: 30 rivulus, 30 blue acara, 30 pike cichlid Guppy Total Population: 210 Number of Generations: 10 Number of Weeks: 286 Data Collected Data Analysis 100% Brightest Bright Drab Drabbest 90% Percent of total population 80% Number of (relative frequency) 4 11 25 170 70% Guppies 60% Percent of 50% 40% Population 2% 5% 30% (rounded) 20% 10% t ht b t es es ra ig ht bb D Br ig ra Br D Color Teacher Resource 245 Pre-AP Biology © 2021 College Board BIO_U2_TR.indd 245 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution PERFORMANCE REFLECTION QUESTIONS TASK 1. Which type of guppy is most successful in this environment? 2. Why do you think this is the case? What is the advantage of this common phenotype in this environment? Experimental Site 2 Information River Site: Shallow pool Number and Type of Predators: 30 rivulus Guppy Total Population: 236 Number of Generations: 10 Number of Weeks: 265 Data Collected Data Analysis 100% Brightest Bright Drab Drabbest 90% Percent of total population 80% Number of (relative frequency) 204 18 5 9 70% Guppies 60% Percent of 50% 40% Population 30% (rounded) 20% 10% t ht b t es es ra ig ht bb D Br ig ra Br D Color REFLECTION QUESTIONS 1. Which type of guppy is most successful in this environment? 2. Why do you think this is the case? What is the advantage of this common phenotype in this environment? Pre-AP Biology 246 Teacher Resource © 2021 College Board BIO_U2_TR.indd 246 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution 3. How does this result differ from Site 1? If the results are different, provide some PERFORMANCE TASK reasoning as to why. Experimental Site 3 Information River Site: Pool behind natural dam Number and Type of Predators: 30 pike cichlid, 30 blue acara Guppy Total Population: 218 Number of Generations: 9 Number of Weeks: 220 Data Collected Data Analysis 100% Brightest Bright Drab Drabbest 90% Percent of total population 80% Number of (relative frequency) 2 98 111 7 70% Guppies 60% Percent of 50% 40% Population 30% (rounded) 20% 10% t ht b t es es ra ig ht bb D Br ig ra Br D Color REFLECTION QUESTIONS 1. Which type of guppy is most successful in this environment? 2. Why do you think this is the case? What is the advantage of this common phenotype in this environment? Teacher Resource 247 Pre-AP Biology © 2021 College Board BIO_U2_TR.indd 247 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution PERFORMANCE 3. How does this result differ from Sites 1 and 2? If the results are different, provide TASK some reasoning as to why. PART 2: DRAWING CONCLUSIONS 1. For each of the three experimental sites, examine the number of weeks that the study lasted. Explain why you think Endler waited this length of time to collect data. Use one or more of the data sets to help illustrate your explanation. 2. Endler also noticed that even the colors in the drabbest male guppies varied from one another in different areas of the river. (a) What could be a cause for this difference in coloration? (b) If a drabbest male was moved from one area of the river to a new area, how might the selective pressures change the guppy’s fitness? 3. Analyze the two claims made on the next page. For each one, decide whether the information provided in the reading and data sets supports or refutes that claim. Then provide evidence and reasoning to support your decision. Pre-AP Biology 248 Teacher Resource © 2021 College Board BIO_U2_TR.indd 248 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution Claim 1: When very few predators are present, the most fit color variation is the PERFORMANCE TASK drabbest male. Support or Refute? Evidence Reasoning (from reading and/or data sets) Claim 2: When many predators are present, the most fit color variation is the drabbest male. Support or Refute? Evidence Reasoning (from reading and/or data sets) Teacher Resource 249 Pre-AP Biology © 2021 College Board BIO_U2_TR.indd 249 13/04/20 9:53 PM  Performance Task: The Flashy Guppy Data Analysis Unit 2: Evolution PERFORMANCE 4. Using the background information and data sets, craft another claim about what TASK occurs when there are moderate numbers of predators in the environment. Be sure to support your claim by using the evidence provided. Justify your claim and evidence with reasoning about natural selection principles. Claim: Evidence Reasoning (from reading and/or data sets) 5. Conclusion: Make a claim about whether natural selection is acting on the color variations in guppies. Use evidence from the background reading and data sets and reasoning to support your claim. If there is a line of evidence that is missing but necessary for your claim to be supported, identify it. Pre-AP Biology 250 Teacher Resource © 2021 College Board BIO_U2_TR.indd 250 13/04/20 9:53 PM