Skin Color and Human Evolution
This activity guides the analysis of a published scientific figure from a study that investigated genetic factors contributing to skin color differences, particularly within African populations.
In this study, scientists identified genomic regions that were significantly correlated with skin color differences. The most significant correlation between variation in skin color and variation in genetic sequence in Africans was at a gene called SLC24A5. This gene codes for a protein that affects the production of melanin, a pigment that gives skin its color and protects against ultraviolet (UV) radiation. The left panel of the figure shows global erythemal dose rate as a proxy for average UV exposure. The right panel shows the proportions of different populations with one of two alleles (“G” or “A”) of the SLC24A5 gene.
The “Educator Materials” document includes a captioned figure, background information, graph interpretation, and discussion questions. The “Student Handout” includes a captioned figure and background information.
Student Learning Targets
- Analyze and interpret data from a scientific figure.
- Describe how genetic variations can contribute to differences in skin color.
allele, genome-wide association study (GWAS), genotype, heat map, melanin, mutation, pie chart, pigmentation, single nucleotide polymorphism (SNP), ultraviolet (UV) radiation
Nicholas G. Crawford, Derek E. Kelly, Matthew E. B. Hansen, Marcia H. Beltrame, Shaohua Fan, Shanna L. Bowman, Ethan Jewett, et al. “Loci associated with skin pigmentation identified in African populations.” Science 358, 6365 (2017). https://doi.org/10.1126/science.aan8433.
HS-LS3-2, HS-LS4-4; SEP2, SEP4, SEP5
SYI-3.B; SP1, SP4
3.1, 3.4, 5.2, 10.2
Topic(s): 2.6, 9.1, 4.7
Learning Objectives & Practices: ERT-2.H, STB-4.A, ENG-2.A, SP5
Math.S-ID.6, Math.S-IC.4; MP2, MP5
CC1, CC3; DP2