Using Carbon Isotopes in Astrobiology: Origin of Life and beyond
Summary
Carbon isotopes are used in many different ways by scientists to reconstruct Earth's past. For example, we can use carbon isotopes to determine when life first evolved on Earth, and to learn more about what types of foods ancient animals ate. We can use carbon isotopes this way because of one simple fact - when photosynthetic organisms like algae and plants take up carbon dioxide and change it into organic matter (i.e., their bodies), they fractionate carbon, leaving behind a chemical fingerprint of their work. This activity will walk students through a model of stable carbon isotopic fractionation using bingo chips (or similar), ask them to apply their new understanding to data on the origin of life on Earth, and then think more broadly about the role of isotopes in astrobiology.
Context
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How the activity is situated in the course
Goals
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Description and Teaching Materials
This activity will walk students through a model of stable carbon isotopic fractionation using bingo chips (or similar) and then ask them to apply their new understanding to data on the origin of life on Earth, then think more broadly about the role of isotopes in astrobiology.
It includes a student handout and a set of teaching slides. Ideally, the teaching slides would be used in a class period before the activity, or as a pre-lab pre-recorded lecture by the instructor.
Bingo chips are used in the handout, but many other objects can be used as well such as candies, coins, and beads.
In a large class, this can be done using a document camera with a few student helpers at the front of the room.
This activity was created with support from the National Science Foundation EAR 1855014
Student Handout for Using Carbon Isotopes in Astrobiology: Origin of Life and beyond (Acrobat (PDF) 1.1MB May19 22)
Teaching slides on stable carbon isotopes (PowerPoint 2007 (.pptx) 11.6MB May19 22)