Question

The correct sequence of events depicting Darwin’s theory of evolution is
I. Natural selection
II. Struggle for existence
III. Appearance of variations
IV. Overproduction

• A. I–IV–III–II
• B. IV–II–III–I
• C. IV–I–III–II
• D. IV–III–II–I

Answer 1

Answer: (B)

The theory was given by Charles Darwin – Theory of Natural Selection:
1. All living organisms possess enormous reproductive potential.
2. Struggle for existence: Limitation of food and shelter leads to a struggle for existence which is of following types –
A. Intraspecific struggle (the most acute type of struggle)
B. Interspecific struggle (most potent force for evolution)
C. Extraspecific struggle
3.Variations and heredity: According to Darwin, every population has built-in variations in characteristics. In fact, no two individuals are alike. Only continuous and useful variations are the raw material of evolution.
4. Natural selection (or Survival of the fittest): Only those organisms will survive which possess the most useful variations. This has been called Natural selection by Darwin and Survival of fittest by Herbert Spencer. The fitness, as per Darwin refers ultimately refers to Reproductive fitness.
5. Favourable variations accumulate over generations to ultimately result in speciation.