The Evolution of Human Skin Color
Continuing Studies and Executive Education
While the concept of evolution by natural selection is very simple, it is often misunderstood by students. This is partly due to preconceptions they have as well as a lack of understanding or emphasis on the idea that reproductive success (and not survival) is what matters to evolution. One way to ensure that students grasp this concept is to confront them with situations that require them to examine each factor’s effect on survival and reproduction. In this case study, the evolution of human skin color is used as a means of exploring the process of evolution by natural selection. Through the progressive disclosure of data, students learn about are the factors that may have exerted pressure on the evolution of this trait. Students evaluate hypotheses, predict their outcomes, evaluate them in light of new information, and reformulate them to take unexplained data into consideration. The case has been used in a first-year introductory biology course for non-majors.
- Formulate testable hypotheses given preliminary data.
- Predict patterns that would confirm their hypothesis.
- Interpret data and compare to predicted outcomes.
- Reformulate hypotheses when in conflict with existing data.
- Identify factors that can exert evolutionary pressures (discriminate between factors that affect reproduction and those that affect survival).
- Apply the concepts of natural selection to a real situation.
- Evaluate whether sexual selection is affecting a human trait.
- Propose public policies and practices based on assimilated information.
KeywordsSkin pigmentation; skin color; natural selection; evolution; vitamin D; vitamin B folate; ultraviolet light; UV light
Educational LevelHigh school, Undergraduate lower division
Type MethodsDiscussion, Interrupted
Subject HeadingsEvolutionary Biology Biology (General) Science (General) Cell Biology
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The following video(s) are recommended for use in association with this case study.
- The Biology of Skin Color
In this short video, Penn State University anthropologist Dr. Nina Jablonski walks us through the evidence that the different shades of skin color among human populations arose as adaptations to the intensity of ultraviolet radiation in different parts of the world. Running time: 18:58 min. Produced by: HHMI BioInteractive.