ICE STATION SHEBA: THE WARMING ARCTIC

The Food Chain
A concept that can be compared to the ripple effect is that of a food chain. Leland G. Johnson, in his university text book Biology, defines a food chain as “A sequence of organisms through which energy and materials move in an ecosystem. [This] includes producers and consumers.” A grazing food chain involves plants taking energy from the sun which, for example, is then passed on to grasshoppers who eat the plants. Some of the energy in grasshoppers ends up in the meadowlarks that feed on the insects. In turn, the meadowlarks pass along energy to Cooper’s hawks when they are taken by the hawks for food.

In this News in Review report, scientist Buster Welch mentions an example of a ripple effect in a food chain. If the ice cap melts, those on the bottom of the food chain will benefit while those on the top will not. Review what Welch has to say about this food chain, explain the phenomenon, and suggest why this is of particular significance to the Arctic.

A Great Chain of Being
A philosophical concept that can be compared to a food chain is that of the Great Chain of Being, an idea explored by Saint Thomas Aquinas (1225-1274), a Christian theologian and philosopher who held that the truths of faith complement those of reason. He believed that the Great Chain of Being extended beyond humans to include angels and finally God. A key difference, however between the Great Chain of Being and a food chain is how far the “chain of command” or authority extends. Just as the content of the two chains is different, so are the ripple effects that are possible in each. The traditional Christian concept that God is at the top of the Great Chain of Being and that God has told humans they “have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth” suggests a vital role on earth for humans in terms of the other inhabitants of the planet. But what is the nature of such dominion, a word that suggests authority, power, control, and supremacy? If human beings, through their knowledge and technological advances do indeed have such dominion, how should it be exercised? What is the responsibility inherent in such dominion?

In what ways do the mandate and work of SHEBA suggest philosophic or moral issues that also evoke the image of a chain of being?

Follow-up Activity
1. The grazing chain mentioned above is only one of many possible food chains. In groups of three or four, make charts of other possible food chains. Try to use knowledge you already have of the world around you. Consider especially the human food chain. What foods are contained in this extensive food chain? Do you find there are some foods that you would include in the chain that others might not? Make note of these items, and when you come together as a class, suggest reasons why foods vary among different cultures.