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| Natural Selection gives individuals with an advantageous trait a better chance to reproduce and further their genetic line. | The second important basis of Darwin’s theory is a process
called Natural Selection. Selection is the most important factor
in evolution and provides the step of choosing the organism best adapted
to its environment. Darwin’s idea was that hereditary traits provide
individuals with a greater chance of survival and reproduction.
Darwin also proposed that there were different types of selection. The most controversial he proposed was sex selection. This states that females, perhaps having more practical bodies, have a greater advantage over males with their more awkward bodies, in some populations. An example of this type of selection is the male peacock. His tail is oversized and brightly coloured. The female, on the other hand, is plain coloured and small tailed. The male’s tail is used to attract the female for mating, though often it attracts predators also. His large tail also hinders his escape and often he ends up as dinner. Stabilising selection is always occurring in every population.
It kills off individuals with excessive abnormalities or mutations.
Many of these mutants die either before birth or immediately after birth.
Directional Selection is a process that increases the number of individuals
with an extreme observable characteristic. It usually results in
the gradual replacement of genes within a genepool. (A genepool is made
up of all the alleles of all the genes of every individual in the species).
Natural Selection gives individuals with an advantageous trait a better
chance to reproduce and further their genetic line. Over time a stronger
population is produced and unreliable characteristics are lost.
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Your say: What is your opinion on evolution? |
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A look at plant and animal life especially adapted to its surroundings. |
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