Question

Write some points on theory of natural selection.​

Answer 1

Some important points on theory of natural selection are as follows:-

1. This theory was proposed by Charles Robert Darwin.

2. He was born in 12th Feb in 1809 in England.

3. Darwin started travelling by H.M.S. Beagle ship, which was started on 27 Dec. 1831 and then returned back on 02 Oct. 1836 via South America, South Africa, Australia & Galapagos Islands.

3. Darwin was very influenced by two books

• (i) Malthus's book which gives information about "Principles of population".
• (ii) Charles Lyell's book that is "Principles of geology".

4. Even he itself written a book in 1859.

5. This whole theory was again explained by Darwin itself in his own book in book "On the origin of species by means of Natural selection".

Answer 2

Answer:

⬛ Principles of Darwin's Theory of Natural Selection are as follows:-

1) Rapid multiplication and over production - Every living organisms multiply by the process of reproduction. Thus they increase in number in geometric progression.

2) Prodigality of production - Even though all species produce a large number of offsprings, population remains more or less constant. This means more youngs are produced than to survive. For example, a female Ascaris ( round worm) produces about 7,00,000 eggs in 24 hours.

3) Constancy of food and space - Amount of food and space in a particular area remains more or less constant although the organisms increase in number.

4) Struggle for existence - A struggle between members of same species and of different species for food and space is called struggle for existence.

5) Variation - No two organisms are exactly same. So, there are differences among the organisms and these differences are called as variation.

6) Survival of the fittest - The individuals, which can adapt themselves with the environmental conditions are successful in struggle for existence.

7) Natural Selection - The individuals possessing favorable variation enjoy a competative advantage over the others.

8) Inheritance of useful variation and origin species - The favorable variation of selected organisms gradually accumulate by reproduction generation after generation and unlimited this may give rise to a new species known as " Origin of Species".