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Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.
This picture is an example of early autrophs.
Click on image for full size
Image courtesy of Corel Photography

Early Life

Over a very long time, gradual changes in the earliest cells gave rise to new life forms. These new cells were very different from earlier cells because they were able to get their energy from a different source -- the Sun.

Organisms that are able to make their own food by using the energy of the Sun are called autotrophs. Photosynthesis is the name of the process by which these autotrophs eat.

Because the autotrophic bacteria were able to feed themselves by using the energy of the Sun, they were no longer dependent on the same limited food supply as the earliest life and were able to grow and multiply. Over millions of years of evolution, these sun loving bacteria eventually led to modern day plants.

The appearance of organisms capable of photosynthesis was very significant -- if it weren't for the photosynthetic activity of these early bacteria, Earth's air would still be without oxygen and animals which need oxygen, including humans, could never have even begun!

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"Science, Evolution, and Creationism", by the National Academies, provides fascinating background on these topics for all, and is particularly useful for the Earth and space science classroom. Check our other books in our online store.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF