Dating Corn Domestication Using Carbon Isotopes

Topic
Resource Type
Description
This activity guides the analysis of a published scientific figure from a study on prehistoric human food sources. In this study, scientists used carbon isotopes to determine how the advent of agriculture affected human diets.
Different types of plants contain different ratios of carbon isotopes. When animals eat plants, the carbon isotopes are stored in their tissues, including bone collagen. In this study, scientists measured carbon isotopes in early human skeletons from North American. The figure shows data of carbon isotope ratios from skeletons found in Illinois, Ohio, and West Virginia dated 4000 BCE to 1500 CE. Each point corresponds to a different location; the numbers and sexes of the individuals found at that location are shown in parentheses.
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. The original article is also provided as a download.
The “Resource Google Folder” link directs to a Google Drive folder of resource documents in the Google Docs format. Not all downloadable documents for the resource may be available in this format. The Google Drive folder is set as “View Only”; to save a copy of a document in this folder to your Google Drive, open that document, then select File → “Make a copy.” These documents can be copied, modified, and distributed online following the Terms of Use listed in the “Details” section below, including crediting BioInteractive.
Student Learning Targets
- Analyze and interpret data from a scientific figure.
- Describe how isotope analysis can be used to reconstruct ancient diets.
Estimated Time
Key Terms
agriculture, anthropology, C3 and C4 carbon fixation, carbon-12 (12C), carbon-13 (13C), error bar, isotopic signature, maize, paleontology, scatter plot
Primary Literature
van der Merwe, N. J. “Carbon Isotopes, Photosynthesis, and Archaeology: Different pathways of photosynthesis cause characteristic changes in carbon isotope ratios that make possible the study of prehistoric human diets.” American Scientist 70, 6 (1982): 596–606. https://www.jstor.org/stable/27851731.
Terms of Use
Please see the Terms of Use for information on how this resource can be used.
Accessibility Level (WCAG compliance)
Version History
NGSS (2013)
HS-LS4-1; SEP2, SEP4, SEP5
AP Biology (2019)
ENE-1.A, EVO-1.N; SP1, SP4
IB Biology (2016)
5.1, D.1
AP Environmental Science (2020)
Topic(s): 5.3
Learning Objectives & Practices: EIN-2.C, SP5
IB Environmental Systems and Societies (2017)
5.2
Common Core (2010)
ELA.RST.9-12.7
Math.S-ID.3, Math.S-IC.1; MP2, MP5