Monday, 7 May 2007

Biology [[Classification, Selection and Evolution]] Darwin-Theory of Evolution by Natural Selection

The original thoery that natural selection might be a mechanism by which evolution could occur was put forward inependantly by Charles Darwin and Alfred Russel Wallace.

They knew nothing of gene mutations nor understood about natural variation and inheritance. There observations are summarised below:

Observation One: Organsism produce more offspring than are needed to replace parents
Obervation Two: Natural populatiosn tend to remain stable in size over long periods

Deduction One: There is a competition for survival

Observation Three: There is variation among the individuals of a given species

Deduction Two: The best adaptad variants will be selected for by the natural conditions operating at the time. Natural selection will occur. 'survival of the fittest'


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