If We Are What We Eat, Americans Are Corn and Soy
Description: This CNN story and journal article show how big a role corn plays in the diet of typical Americans. Scientists can do isotope analysis of the carbon to determine the source of carbon. Corn production is heavily subsidized in the US and relies on large amounts of fertilizers and water.
Web Resources: If we are what we eat, Americans are corn and soy - CNN, Carbon and nitrogen stable isotopes in fast food: Signatures of corn and confinement - PNAS
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Reconstructing Ancient Diets with Isotopes
Description: Scientists are able to reconstruct the diet of ancient humans by analyzing the isotopes found in their bones and hair. For example by examining the 12C/13C isotope ratio they can determine if the diet was mainly wheat (a C3 plant) or corn (a C4 plant). They can also place the diet in different trophic levels based on the isotopes of carbon as well as nitrogen and oxygen. This phenomenon could start with the following question: Was the paleo diet truly the paleo diet?
Web Resource: Reconstructing Ancient Diets with Isotopes - Wikipedia
Biosphere 2
Description: Biosphere 2 was created in the 1990's to model all the elements of Biosphere 1 (The Earth). Plants in the biosphere produced oxygen and food for the inhabitants. The carbon dioxide released during respiration was taken in by the plants cycling the matter with energy from the Sun. In this experiment oxygen levels steadily fell to dangerous levels and oxygen eventually had to be added to the biosphere. This large-scale phenomenon continues to be owned and run by the University of Arizona. The mystery of missing oxygen could be used as a phenomenon in a unit on matter cycling and energy flow. Students can even create biospheres of their own and monitor life over time.
Warning: This video contains strong language (11:06) and is not appropriate for younger viewers. Please use teacher discretion when showing segments of this video directly to children.
Web Resource: Biosphere 2 - Wikipedia
Attack Of The Killer Fungi
Description: The cordyceps fungi has a fascinating life cycle. Spores from the fungi are ingested by an insect (like an ant). The fungi takes over the insect causing it to climb to a high branch and hold tight with its mandibles. A fruiting body then emerges from the head of the insect and spreads more spores that infect more insects. Different species of cordyceps infect different species of insects. This phenomenon can be used to introduce the diverse and unique life cycles found in organisms.
Web Resource: Cordyceps Fungi - Wikipedia
12 Years in a Sealed Ecosphere
Description: The Ecosphere in this video has been sealed in a glass container for 12 years. No air or food was able to enter or leave the Ecosphere during this entire time yet the shrimp are all still alive. This phenomenon can be used in the elementary science classroom to introduce plant and animal needs. It can be used in middle and high school to address matter cycling and energy flow.
Web Resources: Ecosphere (aquarium) on Wikipedia, Ecospheres
Ecosphere Sealed for Over 50 Years
Description: According to this Daily Mail article David Latimer has had a sealed ecosphere for over fifty years that he has only watered once.
Web Resource: Daily Mail article
