Darwin's theory of natural selection
Answer :
i) Charles Darwin had collected innumerable specimens of plant and animals and depending upon the observations of those specimens; he published the theory if natural selection which preaches the survival of fittest.
ii) For this purpose, Darwin had published a book titled 'Origin of Species'.
iii) While explaining the concept, Darwin said that al the organisms reproduce prolifically. All the organisms compete with each other in a life threatening manner.
iv) In this competition, only those organisms sustain which show the modifications essential for winning the competition.
v) However, besides this, natural selection also plays important role because nature selects only those organisms which are fit to live and the res perish.
vi) Sustaining and selected organisms can perform reproduction and thereby give rise to the new species with their own specific characters.
vii) Darwin's theory of natural selection was widely accepted for long duration. However, some objection were raised against the theory. Some of the main objections are -
1) Natural selection is not the only factor responsible for evolution.
2) Darwin did not mention any explanation about useful and useless modifications.
3) There is no explanation about slow changes and abrupt changes.