Exploratour - The Archean Age

The Miller Urey experiment helped show how it was possible to derive some of the components of life from isolated molecules.
Corel Photography

In the 1950's, Stanley Miller and Harold Urey, conducted an experiment which demonstrated that some of the basic elements of life could be formed by simulating the conditions of Earth's early atmosphere. No one really knows exactly how life was formed on the Earth. In whatever way that life on Earth came to be, by 3.8 BYA, (very early in the history of the Earth!), life on Earth included both early autotrophs and early heterotrophs.

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 by which these autotrophs eat. Organisms which require food from sources outside themselves are called heterotrophs, meaning "other-feeders". Because autotrophic bacteria were able to feed themselves by using the energy of the Sun, they were not dependent on a limited food supply and were able to flourish.

The appearance of these organisms capable of performing photosynthesis was of monumental significance -- if it weren't for the photosynthetic activity of these early bacteria, Earth's atmosphere would still be without oxygen and the appearance of oxygen-dependent animals, including humans, would never have occurred!

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