Question

what principal is natural selection based on?

Answer 1

The Darwinian principle of Origin of Species Natural Selection is based on " Survival of the fittest".

The theory of Natural Selection is based on 2 principles

1. The first one is rapid multiplication in a geometric progression

2. The second one is offspring always vary from parents, though generally very closely resembling them.

From the first law there is a constant struggle for existence as the offspring always exceeds in number to an enormous extent. Consequently every year, on the average, as many die as are born. There is thus a perpetual struggle among them which shall live and which shall die and this struggle is tremendously severe, because so few can possibly remain alive. All the individuals of each species were exactly not alike and they vary in many different ways in which some are stronger, some swifter, some hardier in constitution, some more cunning. Of all any beneficial variations will give possesors a greater probability of living through tremendous ordeal. But on the whole the fittest will survive.

Another important fact to consider is principle of heredity or transmission of variations. With the variations, an improvement will take place and the average quality of our stock will be raised. Darwin proved that if any particular kind of variation is preserved and bred from, the variation itself goes on increasing in amount to an enormous extent; and of this the origin of species is most important. Each generation of a given animal or  plant the fittest survive to continue to breed causes “fitness” in the particular case, that peculiarity will go on increasing and strengthening so long as it is useful to the species.

By the continuous survival of the fittest or the preservation of favoured races in the struggle for life, new species may be originated.