14.3: Human Skin Color Variation - Part II
- Page ID
- 138559
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Human Skin Color Variation - Part 2
A close-up photograph of human skin
Learning Objectives
- Evaluate the hypothesis that human skin color tones differ in relation to levels of ultraviolet radiation exposure.
- Summarize the positive and negative selective factors that account for differences in human skin colors.
Supplies Needed
- Internet access
- Worksheet (provided)
Readings
Introduction
Steps
- Students watch the film The Biology of Skin Color produced by HHMI BioInteractive. This film explores the hypothesis that different tones of skin color in humans arose as adaptations to the intensity of ultraviolet radiation in different parts of the world.
- Similar to step one, students answer a series of questions and then draw a diagram that illustrates the positive and negative selective factors that account for the differences in skin colors among human populations.
- Finally, students write one or two paragraphs, summarizing what they have learned in this activity. Writing as if they were talking to a friend who knows little about this subject, they explain how skin pigment is produced and why it varies among people throughout the world
Tips and Suggestions
Adapting for Online Learning
For Further Exploration
- American Anthropological Association. Understanding Race Project.
- Jablonski, Nina G. 2012. Living Color: The Biological and Social Meaning of Skin Color. Berkeley, CA: University of California Press.
- Jablonski, Nina G. 2004. “The Evolution of Human Skin and Skin Color.” Annual Review of Anthropology 33 (2004): 585–623.
References
Image Attributions
Human Skin Color Variation Part 2 Worksheet
Step Two: Understanding the Evolutionary Pressures of Skin Color
- What color skin do chimpanzees have under their fur?
- What type of melanin do lightly pigmented people have?
- What type of melanin do more darkly pigmented people have?
- What other body parts does melanin color? What does melanin do for other species?
- What kind of raw data helped Dr. Nina Jablonski find the answer to her questions about the relationship between UV radiation and human skin pigmentation?
- In general terms, how is UV radiation intensity distributed throughout the world?
- How do scientists measure skin color?
- Why are folate and vitamin D important nutrients?
- Describe the selective pressures for the production of darkly pigmented skin in areas with high UV radiation intensity.
- Describe the selective pressures for the production of lightly pigmented skin in areas with low UV radiation intensity.
- Describe the evolutionary interplay between folate and vitamin D.
- What do scientists infer from the lack of variation in the MC1R gene among African populations?
- Why are light skinned people at greater risk for skin cancer than dark skinned people?
- Why might dark skinned people living in high latitude environments need to take a vitamin D supplement? (Note: please always consult your doctor before starting any supplement regimen).
- Now design a diagram that illustrates the positive and negative selective factors that account for the differences in skin colors among human populations.