In ISB202, Spring Semester 2020, the first high-impact assessment is applying nature of science and scientific literacy concepts to a case study on the biology of skin color. The worksheet and corresponding answers are included below. The full grading rubric can be found by clicking the attachment.
Part 1: The Investigation
1. Consider the research question: “Is there a connection in the intensity of UV radiation and skin color?” What type of study did they perform to investigate this question (observational study, modeling study, or experiment)?
Modeling or observational study are acceptable answers.
2. Explain some of the key components of the study that explain your choice for question #1. Make sure to include specific components (e.g., if there is a control and experimental group, then what were they? If not, then how do you know?). Answer in 2-3 sentences.
Modeling: maps are models showing distribution of skin color and UV radiation
Observational: collected data and did not have a control and experimental group- would not make sense with this research question to do an experiment
3. Evaluate the study’s methods. For instance, what kinds of things were held constant (for example, when we compared different models of the tube activity, each model developer had access to the same materials)? What was the sample size and did it use replicates? Consider different factors that we discussed during Week 2. Evaluate the methods; do not just create a list. Answer in 3-4 sentences.
Answers will vary, such as constants being using similar tools for measuring skin color and UV radiation
4. After they created the two maps (one for UV exposure and one for skin color), what was the resulting conclusion? Make sure to consider this part of the study and not the entire video.
Correlation between skin color and UV radiation (they may make a causal statement, which is also used in the video)
Answer should be the causes of this correlation (such as folate and vitamin D)
5. Describe a general pattern in the maps (i.e., the data) that support the conclusion that you described for question #4. Then explain two specific examples that support it.
The general pattern of darker skin in areas with more UV radiation and they will need two specific examples; they might describe higher elevations also correlating with darker skin (and more UV radiation)
6. After viewing the entire video, what kinds of questions do you have? Develop one testable, scientific research question that extends the research (no just replicate it).
Answer varies but should be testable and not just ethical questions- it is fine if the question is a natural science or social science question.
Part 2: Data Analysis
7. The graph below summarizes the age at which people are diagnosed with melanoma, the most serious form of skin cancer. Consider the claims made throughout the video. Does this graph support or refute a claim in the video? Complete “a” and “b” below to answer this question.
A. Describe the relevant claim in one sentence:
Darker skin (may also mention eumelanin) is selected for to protect folate, an important vitamin for preventing birth defects; it is not selected for to prevent skin cancer
B. Do the data in the graph support or refute the claim? Explain your reasoning in 2-3 sentences.
Majority of people get skin cancer after 45 years of age, which is after reproductive years- natural selection cannot act after reproductive years because it does not affect the probability of getting genes to the next generation.
Part 3: Controversies
8. Describe one scientific controversy mentioned in the video- either current or resolved. Describe the specific evidence and define “scientific controversy” within your explanation. Answer in 3-5 sentences.
The main controversy that students may describe is why dark skin was selected for. Originally thought it was due to protect against skin cancer, which evidence does support that those with darker skin are less likely to develop skin cancer. However, new evidence suggests that it is to protect folate after it was showed to be important in preventing birth defects and can be damaged by UV radiation.
The controversy must be a scientific controversy, not an ethical one.