One of Darwin's principles is that minor variations in all traits exist within species. Why is this idea important to his theory of evolution?
Answers
Darwin's theory of evolution is based on the fact that individuals in a population possess different variations and that favourable variations are selected by nature.
The Natural Selection theory opines that individuals with beneficial variations will survive longer and will produce more number of progeny. Thus variations which help an organism to adapt to its environment get selected in every generation.
We know that most variations are written in genetic code, thus inheritable. We may say that there will be an increase in percentage of those alleles which control beneficial traits, over a long period of time. Favourable variations will continue to accumulate in the genepool of a species. Moreover different variations would allow successful adaptation to different environments.