BU Graph Analysis Discussion – Description
Step 1:
Re-read Carly’s study on Coral bleaching and climate change: Corals are animals that build coral reefs. Coral reefs are home to many species of animals – fish, sharks, sea turtles, and anemones all use corals for habitat! Corals are white, but they look brown and green because certain types of algae live inside them. Algae, like plants, use the sun’s energy to make food. The algae that live inside the corals’ cells are tiny and produce more sugars than they themselves need. The extra sugars become food for the corals. At the same time, the corals provide the algae a safe home. The algae and corals coexist in a relationship where each partner benefits the other, called a mutualism: these species do better together than they would alone.When the water gets too warm, the algae can no longer live inside corals, so they leave. The corals then turn from green to white, called coral bleaching. Climate change has been causing the Earth’s air and oceans to get warmer. With warmer oceans, coral bleaching is becoming more widespread. If the water stays too warm, bleached corals will die without their algae mutualists.Carly is a scientist who wanted to study coral bleaching so she could help protect corals and coral reefs. One day, Carly observed an interesting pattern. Corals on one part of a reef were bleaching while corals on another part of the reef stayed healthy. She wondered, why some corals and their algae can still work together when the water is warm, while others cannot? Ocean water that is closer to the shore (inshore) gets warmer than water that is further away (offshore). Perhaps corals and algae from inshore reefs have adapted to warm water. Carly wondered whether inshore corals are better able to work with their algae in warm water because they have adapted to these temperatures. If so, inshore corals and algae should bleach less often than offshore corals and algae. Carly designed an experiment to test this. She collected 15 corals from inshore and 15 from offshore reefs in the Florida Keys. She brought them into an aquarium lab for research. She cut each coral in half and put half of each coral into tanks with normal water and the other half into tanks with heaters. The normal water temperature was 27°C, which is a temperature that both inshore and offshore corals experience during the year. The warm water tanks were at 31°C, which is a temperature that inshore corals experience, but offshore corals have never previously experienced. Because of climate change, offshore corals may experience this warmer temperature in the future. After six weeks, she recorded the number of corals that bleached in each tank.
Re-read Alycia’s study on Fish territories and aggression: In many animals, males fight for territories. Getting a good territory and making sure other males don’t steal it is very important! Males use these territories to attract females for mating. The males that get the best territories are more likely to mate with females and have more babies. Only the males that have babies will pass on their genes to the next generation.Stickleback fish use the shallow bottom areas of lakes to mate. Male stickleback fish fight each other to gain the best territories in this habitat. In their territories, males build a nest out of sand, aquatic plants, and glue they produce from their kidneys. The better the nest, the more females a male can attract. Males then use courtship dances to attract females to their nests. If a female likes a male, she will deposit her eggs in his nest. Then the male will care for those eggs and protect the offspring that hatch.Alycia is a scientist who is interested in understanding what makes a male stickleback a good fighter and defender of his territory. Perhaps more aggressive males are better at defending their territory and nests because they are better at fighting off other males. She used sticklebacks she collected from British Columbia to test her hypothesis.In her experiment, 24 males were kept in 6 large tanks, with 4 males in each tank. Alycia watched each of the 24 males every day for 10 days. She recorded the behaviors of each fish when they were competing for territories, defending their territory, and building their nests. She also recorded the size of the males’ territories and whether they had a nest each day.
Step 2:
Re-read the Observation, Question, Hypothesis, and Prediction from those experiments:
1. What observation(s) did Carly make before proposing her experiment?Carly observed that corals on one part of a reef were bleaching while corals on another part of the reef stayed healthy. She also knew from previous studies that ocean water that is closer to the shore (inshore) gets warmer than water that is further away (offshore).
2. What research question did Carly want to answer? Must write in question format.Carly wanted to know why some corals and their algae can remain in their mutualistic relationship even when the water is warm, while others cannot?
3. What was the hypothesis that Carly wanted to test?Carly’s hypothesis was that inshore corals may be better able to work with their algae in warm water because since they experience warmer temperatures being closer to the shore they have already adapted to warmer temperatures.Keep in mind that a scientific hypothesis must be:Preliminary ->The answer is not yet known
Mechanistic -> Seeks to define cause/effect relationship
Explanatory -> Explains how an underlying process mediates an observed effect4. What did Carly predict would happen based on her hypothesis?If Carly’s hypothesis was true, she predicted that inshore corals and algae would bleach less often than offshore corals and algae. 5. What type of study did Carly conduct?Carly conducted an experimental study
6. What observation(s) did Alycia make before proposing her experiment?From her reading of the scientific literature, Alycia knew that male stickleback fish fight for territories in shallow areas of lakes and build nests to attract females for mating. The size of the males’ territories and the quality of their nests can affect their ability to attract females.7. What research question did Alycia want to answer? Must write in question format.Alycia wanted to know what factors contribute to a male stickleback being a successful fighter and defender of its territory?
8. What was the hypothesis that Alycia wanted to test?Alycia’s hypothesis was that more aggressive males will be better at defending their territories and nests because they are better at fighting off other males.
9. What did Alycia predict would happen based on her hypothesis?If the hypothesis is correct, Alycia predicted that more aggressive males would have larger territories and better nests, and would be more successful at attracting females for mating.
10. What type of study did Alycia conduct?Although Alycia conducted the study in the lab, her study is more like an observational study since she didn’t assign her study subjects (fish) to particular treatments, as you would see in an experimental study. All fish were housed in the same conditions and she observed for which factors (such as aggressiveness) impacted the size of the territory.
Re-read the answers to Subjects, Variables, and Treatments:
Step 3:
Download Carly’s data attached below
Download Alycia’s data attached below
Step 4:
Carefully study the graphs below from Carly’s and Alycia’s experiments attached below
Your post should include all the items below:
For Carly’s experiment, A) Identify the dependent and the independent variables. B) Are these variables continuous or categorical? C) Identify which variable is plotted on the X-axis and which one is plotted on the Y-axis. D) What are the units of the Y-axis?
Describe the results from Carly’s experiment using the graph. In order to do this, you will need to:
State the question Carly wanted to test.
Briefly describe the experiment that Carly performed, and the variables she measured.
Describe the results from Carly’s experiment using the graph.
Indicate whether the hypothesis was supported or not.
For Alycia’s experiment. A) Identify the dependent and the independent variables. B) Are these variables continuous or categorical? C) Identify which variable is plotted on the X-axis and which one is plotted on the Y-axis. D) What are the units of the Y-axis?
Describe the results from Alycia’s experiment using the graph. In order to do this, you will need to:
State the question Alycia wanted to test.
Briefly describe the experiment that Alycia performed, and the variables she measured.
Describe the results from Alycia’s experiment using the graph.
Indicate whether the hypothesis was supported or not.
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