Zebrafish and Skin Color
In this activity, students explore how experimental work in zebrafish led to a better understanding of the role of the gene SLC24A5 in human skin color. The activity complements the film The Biology of Skin Color.
Variations in the SLC24A5 gene play an important role in the expression of lighter skin tones in people of European descent. Students explore data (primarily graphs, data tables, and illustrations) generated from genetic studies in fish, a model organism, to help them understand the function and evolution of SLC24A5. Students use real data to construct explanations, make predictions, propose hypotheses, and make evidence-based claims.
This activity extends information presented in the film The Biology of Skin Color. In that film, Nina Jablonski proposed an explanation for the evolution of different natural skin tones among populations living in different parts of the world. Specifically, students learned how patterns in variation for the MC1R gene provide evidence that dark skin is favored in environments that experience intense UV radiation. This activity focuses on a different gene.
This activity is adapted from an activity in the Evolution of Human Skin Color curriculum unit for AP Biology that is a part of the Smithsonian Institution’s Teaching Evolution through Human Examples project (NSF Grant No. 1119468).
Student Learning Targets
- Construct explanations, make predictions, and propose hypotheses based on available information.
- Use real data presented in scientific figures and information from the film to make evidence-based claims.
adaptation, allele, frequency, gene, melanin, melanosome, phenotype
Lamason R. L., Manzoor-Ali P. K. Mohideen, Jason R. Mest, Andrew C. Wong, Heather L. Norton, Michele C. Aros, Michael J. Jurynec, et al. “SLC24A5, a putative cation exchanger, affects pigmentation in zebrafish and humans.” Science 310, 5755 (2005): 1782–1786. https://doi.org/10.1126/science.1116238.
HS-LS1-1, HS-LS3-1, HS-LS3-3, HS-LS4-1; SEP4, SEP6
AP Biology (2019)
EVO-1.E, EVO-1.M, EVO-1.N, EVO-3.A, EVO-3.C, IST-1.P, IST-2.E, IST-4.B, SYI-3.D; SP2, SP4, SP6
IB Biology (2016)
3.1, 5.1, 10.2, B.5
AP Environmental Science (2020)
Topic(s): 2.6, 2.7
Learning Objectives & Practices: ERT-2.H, SP5
IB Environmental Systems and Societies (2017)
Common Core (2010)
Math.S-ID.3, Math.S-IC.2; MP2
Vision and Change (2009)
CC1, CC3; DP1, DP2