by Dave Nocera

Created on: November 09, 2008

If you ever saw the beautiful red-rock formations painting Earth's landscape such as Sedona Arizona, the Australian Outback or Savannahs of Africa you are witness to the impacts that the first life had on a very early stage in Earth's History. Earth, along with the rest of the planets of revolving our Sun, was formed about 5 billion years ago. By 3.7 billion years ago Earth's crust solidified and the steam in the atmosphere settled into an ancient ocean rich in iron. The red rock is the rust left behind from that first ocean, and the story of life on Planet Earth starts with that red rock.

Known as iron-oxide, rust comes from the combination of iron and oxygen molecules. The ocean was already rich in iron; the oxygen came from early life. By 3.5 billion years ago, ancient bacteria filled the ocean; it consumed iron for food and metabolizing the iron produced oxygen.
This metabolic process is encoded in the genome of life, it taps the first law of thermodynamics which states that "energy can neither be created nor destroyed. It can only change forms".
Life's first trick was to tap the iron in the ocean for energy. But what did it use that energy for?

Life needed energy to overcome the second law of thermodynamics, also known as entropy. Entropy states that disorder is irreversible in nature, things move towards greater and greater disorder. Eggs don't jump up off the floor and reassemble themselves on the table and an early bacterium could not live forever. Life's second trick was to invent reproduction as a means to overcome entropy. Reproduction is life's way to cheat death, not the death of the individual bacterium, which was doomed by entropy, the death of the species.

By passing genetic information from generation to generation, life could sustain itself.
And it did great until 3.2 billion years ago when the first bacteria created Earth's first energy crisis. The iron suspended in the oceans began to run out, and bacteria needed a new trick to survive; it needed a new energy source.

The oceans were now clear and free of iron with plenty of sunlight; bacteria then added photosynthesis to the genome , bacteria was now powered by the sun. Photosynthesis uses a chemical process to convert sunlight into energy; it also produces oxygen as waste.

By 2.4 billion years ago bacteria created Earth's first pollution crisis. Oxygen is very reactive molecule and after a billion years of producing it, bacteria poisoned the oceans with oxygen and extinction was eminent. Once

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