The Ecosystem

When you see the beautiful blue earth from space you are looking at the largest unit of life as we know it, the whole earth ecosystem
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March31.DSC_4400.smallEveryone is aware of the enormous differences among living things, from one-celled bacteria to the whole earth ecosystem that includes plants, animals, fungi etc., all able to maintain a viable balance within their various environments. Can a giraffe in Africa have anything in common with an acacia tree in Australia and a jellyfish that lives in the ocean? Yes, of course, they are all living things, and all living things — to be alive — have three requirements in common.

1. Energy flows through all living things. Energy is the ability to do work and work is described as anything that moves or changes. Clearly one characteristic of living things is that they move and/or change. Therefore they require energy to be alive.

2. At every level, living things must regulate interactions with the materials in the environment – that is materials such as oxygen, nitrogen, carbon and hydrogen. These are the things that living things are made of.

3. As we mention above, these interactions are too complicated even for a computer to keep track of. Somehow the living organism must find a way to keep track of all this complexity, and it does so by the flow of information through time.

On Monday we will begin with a discussion of energy.