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During the next 1.7 billion years the whole environment changed. Iron minerals in the rocks and oceans of the Earth began to combine with the oxygen and turn brown -- the world began to rust. Gradually the whole chemistry of the Earth was changed.
By 1.8 billion years ago all the minerals in the rocks and oceans had rusted. Now the oxygen made by blue-green bacteria began to build up in the atmosphere, which began to change into the air we know today. Never since has the world seen such a drastic change. This had a terrible effect upon most bacteria. Oxygen attacked many of life's molecules, combining with them, changing their structure and giving out carbon dioxide and heat. It is the process we call burning. Burning can happen quickly, as in a fire, or slowly, as when a cut apple goes brown. The new oxygen slowly burnt the proteins and chromosomes inside the bacteria and most of them died in the Great Oxygen Poisoning, but not all. Some anaerobes hid away in places where there was no oxygen, such as in the mud at the bottom of swamps. They managed to survive in any place without oxygen, and we still find them living there. These are the anaerobic bacteria which make dead matter putrefy, giving off bad smells. Useful LinksClick for Further information about Oxygen Poisoning Other History of the Universe Pages News about History of the Universe |
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