Invasions Of The Land

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Over 400 years ago there was no life on the dry rocky surface of the land because of high levels of ultraviolet light from the sun bombarded the earth. Ultraviolet light damages the DNA. So much light was hitting the earth that life could not survive out of water which absorbs ultraviolet rays. Then life moved onto land because of change in the atmosphere. As large amounts of oxygen diffused into the upper atmosphere ultraviolet rays broke apart some of the oxygen molecules which then recombined to from the ozone. In the upper atmosphere ozone acted like a great shield blocking all of the ultraviolet rays. Over 400 million years ago ozone made the earth a safe place to live.

One of the first things to populate the surface of the land was plants and fungi. Plants evolved from green algae. That makes it able to carry out photosynthesis.

The solution to the challenge of living on dry land was a unique biological partnership between plants and fungi called mycorrhizae. Fungi provides the plant with minerals absorbed from rock or soil. So the plants provide food to the fungi. This kind of "you-help-me… I-help-you" is called mutation. The earliest plants and fossils which lived about 410 million years ago. 80% of plant species have mycorrhizae associated with their roots already.

The first animals to leave the water was anthropods. Crabs and lobsters are examples of existing aquatic anthropods. The continental drift is when the continents slowly move away from each other for the last 2 billion years.

Insects came after anthropods. Today there are more than 200 million individual insects. Plants with flowers have sweet necters or other food. So the flower of plants attracts insects.