The Mighty Bang

Plants evolution and conditions on Earth
At the beginning of the Earth’s history, it was full of volcanic activity. The Earths surface was molten and too hot for any plants of live. Eventually Earth cooled down and was getting nearer to the needs for plants. However volcanoes kept erupting which released carbon dioxide and water vapour into the atmosphere. The atmosphere was thought to be mostly carbon dioxide which was perfect for the life of plants. The water vapour condensed to form the oceans and rivers which provided water for the plants. These perfect conditions made plants take hold of earth. All of these plants photosynthesized which lowered the amount of carbon dioxide and raised the levels of oxygen. The raise in oxygen killed off some simple organisms but allowed more complex organisms to evolve, which eventually led to us.
For a long time photosynthesizing organisms remained in the ocean. This is because of a very simple reason, a lack of ozone filtering out lethal UV rays from the sun. For this reason these organisms only moved to land when the ozone had built up and could survive on land.
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Algae are the oldest living organism known which contains chlorophyll. The timescale for this was about 3 billion years ago. This form of life is found almost everywhere to land, to freshwater, to saltwater, to ice and to even snow. Some forms are extremely complex while others have remained fairly simple. The most common type of algae is green algae. Green algae has more than 7000 types of species growing in all kinds of habitats.
The next stage of evolution was Vascular Plants. An example of this would be a plant such as a fern.
{draw:frame} Vascular plants evolved from green algae but still had a few similarities. For example they all store energy in the form of starch and their cell walls have a similar structure.
Plants have evolved to be extremely specialized to their surroundings. A cactus is extremely adapted...