Question

Briefly discuss the theory of natural selection as given by Darwin.

Answer 1

Hint: The “Theory of evolution” put forward by Darwin has two most important concepts. They are branching descent and natural selection. Survival of the fittest organism occurs and others are not able to survive if they are not adapted to the environment.

Complete answer: The concept of natural selection given by Darwin has many important perspectives. In this theory, he states that when the breeding potential of each species is high, it results in an increased rate of reproduction. This phenomenon is called overproduction. As they reproduce by sexual reproduction, the progenies will be different from their parents and from themselves. As the population is high, there exists a struggle for the natural resources that are limited. This is called the struggle for existence. In this struggle, only organisms that are well adapted with the changing environment survive and all the others die. This is called survival of the fittest. The only fittest organism survives in a changing environment. Here, fitness is measured only by reproductive capability and not other features. It means that individuals that can better adapt to the environment can reproduce and survive better. The survived organisms reproduce and they increase in number. Over years, these would leave more progenies and there would be a change in population characteristics and new forms appear to arise.

Note: According to Darwin’s theory, this whole process works only according to the environment. He believed that the process of evolution is not a predetermined one and its direction depends upon the environmental factors. But this was later opposed by scientists including Hugo deVries. He put forward the theory of mutation and told that evolution is a random and directionless process depending upon mutations that occur in the genetic level.