Advertisements
Advertisements
Question
State Darwin’s theory of evolution.
Advertisements
Solution
- Darwin’s theory of evolution is better known as theory of natural selection.
- Darwin opined that only the fittest can survive. Those plant and animals which are not fit for survival,die.
- The fitter species reproduce in greater numbers and pass on their genes to the next generations. This process of selection of characteristics which contribute to the fitness for survival was termed as natural selection.
- Darwin’s theory of naturals selection emphasises on the fact that there is always overproduction of individuals in nature. This causes a struggle for existence. Only those organisms that have characters useful for survival are selected and hence they survive. While some organisms that do not have favourable characters, perish. This process takes place for many generations.
- As a result the species which are better adapted for survive are selected. The individuals belonging to this species may be different from the originals ones. But if this changed species shows successful adaption and growth in the given environment then it gets evolved.
- The process of natural selection is not deliberate but is gradual and natural. This process further leads to the development of species.
- Darwin’s theory is widely accepted but it has one drawback. It did not explain how the favourable characters were developed in the fit individuals.
- Darwin’s theory is now universally accepted.
APPEARS IN
RELATED QUESTIONS
Give the principles of Darwin's theory of natural selection.
Objection to Darwin's theory of natural selection.
State the two key concept of Darwinian theory.
All organisms produce more young ones. Comment
Answer each question in ‘One’ sentence only:
Identify which one of the following is a test cross.
The theory of Natural Selection was proposed by
Given alongside are two figures (A and B) showing a phenomenon that was first observed in Manchester before and after the year 1850.
Answer the following:
- What name has been given to this phenomenon?
- Give the common name and the scientific name of the insect involved in this phenomenon.
- Briefly mention why the changes shown in the two figures appeared.
- The following phenomenon provides a classical explanation of a scientific theory given by a certain scientist.
- Name and explain the said theory.
- Give the name of the scientist who gave this theory.
Natural selection is a driving force for evolution-How?
Identify the two organisms which are now extinct and are studied from their fossils.
Select the correct statement.
Which one of the following statement is correct?
According to Darwin, two different areas within a continent have different species because they have different:
Origin of species was written by:
Match List - I with List - II.
| List - I | List II | ||
| (a) | Adaptive radiation | (i) | Selection of resistant varieties due to excessive use of herbicides and pesticides |
| (b) | Convergent evolution | (ii) | Bones of forelimbs in Man and Whale |
| (c) | Divergent evolution | (iii) | Wings of Butterfly and Bird |
| (d) | Evolution by anthropo- genic action | (iv) | Darwin Finches |
Choose the correct answer from the options given below.
Nature has a way of causing organisms that inherit advantageous traits to survive and reproduce more successfully than the ones that do not. This process is known as ______.
Industrial melanism was observed in ______.
Charles Darwin explained the origin of species through ______.
Define the following term:
Speciation
