HOW THE FIRST PLANTS AND ANIMALS EVOLVED AND BECAME DEPENDANT ON EACH OTHER

Mutualism is the living together of two species whereby they both benefit from this way of life. The interaction between plants and insects during the process of co-evolution has been beneficial to both of them. “Co-evolution between interactions started in aquatic environment before they evolved on the land. The first species to evolve was the eukaryote”(4). This was discovered through the process of fossilisation and it was found that the eukaryote is multi-cellular animal. These first animals were called eukaryotic because they contain nucleus(1).

Through the process of photosynthesis some plant species can generate their own food. “Single cell plants and blue or green algae are the species that co-evolved and these are the same species that produced their own food. These plants help the herbivore animals to depend on them for food. Plants also help them with oxygen. This is where animals depend mostly on plants for their survival because they are gaining both food and oxygen”(3). So finally plants were considered producers because they use the sun as their source of energy, carbon dioxide from the animals and water to produce food. This is mostly where the food chain begins.

The production of oxygen by algae helps the animal species to evolve on land. "The most part of the O-zone layer is formed by oxygen which blocks the dangerous ultraviolet rays of the sun. If there is no oxygen supplied the rays make it impossible for animal species to live out of the water. In case of the plant the rays help them in food production"(2)

The relationship between plants and animals is very broad. Beside food and oxygen animals still depend on plants for shelter. Many animals use the trees as their habitat, mostly birds because that is where they also lay their eggs for reproduction. During reproduction plants depend on animals mostly insects like bees to transport pollen grains to the female flowers. This is far better than wind on increasing plant population(3).

References:

1. Wikipedia contributors. Eukaryote [Internet]. Wikipedia, The Free Encyclopedia; 2006 May 22, 12:39 UTC [cited 2006 May 25]. Available from: http://en.wikipedia.org/w/index.php?title=Eukaryote&oldid=54516796.

2. Kazlev.A.M. 2002, Plants, (Land plants) [Internet] 2006 May 08; 14:00 UTC[cited 2006 May 08] Available from:
http://www.palaeos.com/Plants/default.htm

3. Kohler, S. Plants, [Internet] 2006 May 8, 14:30. UTC [cited 2006 May 07]. Available from: http://www.blueplanetbiomes.org/plants.htm

4. Stein Carter, J. 1999 Co-evolution [Internet] 2006 May 08; 14:15; [Cited 2006 May 08] Available From:
http://biology.clc.uc.edu/courses/bio303/coevolution.htm

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