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The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.
This picture is an example of early autotrophs.
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Image courtesy of Corel Photography

Early Life

Organisms that are able to make their own food (in the form of sugars) by using the energy of the Sun are called autotrophs, meaning "self-feeders". Photosynthesis is the name of the process through which these autotrophs covert solar energy to biological energy.

Because the autotrophic bacteria were no longer dependent on the same limited food supply as their heterotrophic ancestors, they were able to flourish. Photosynthesis was mostly along sulphur or methane pathways, however, and not the familiar carbon dioxide pathway most plants use today. Moreover, these photosynthetic pathways are not oxygenic (O2 is not produced). The following is an example:


As a result of the activity of these bacteria, S began to build up in the world's atmosphere and oceans. The production of atmospheric O2 became possible only later after the oxidation state of the oceans changed.

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The Spring 2010 issue of The Earth Scientist, focuses on the ocean, including articles on polar research, coral reefs, ocean acidification, and climate. Includes a gorgeous full color poster!

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