Advertisements
Advertisements
प्रश्न
State Darwin’s theory of evolution.
उत्तर
- 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
संबंधित प्रश्न
Explain Darwinian theory of evolution with the help of one suitable example.
Give the principles of Darwin's theory of natural selection.
Give the scientific name of the organism which is cited as the classical example of "natural selection".
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.
List any three drawbacks of Darwinism.
In which book Darwin had published his theory of Natural selection?
The more characteristics two species have in common ______
Natural selection is called ‘survival of the fittest. Which of the following statements best describes an organism?
Wild cabbage has evolved into new varieties like cabbage, broccoli, and cauliflower by ______
If the fossil of an organism is found in the deeper layers of earth, then we can predict that
What are homologous structures? Give an example. Is it necessary that homologous structures always have a common ancestor?
The ship on which Darwin was appointed as Naturalist was:
According to Darwin, two different areas within a continent have different species because they have different:
Species occurring in the different geographical areas are called as ______.
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.
What are the key concepts in the evolution theory of Darwin?
Who proposed the theory of survival of the fittest?
Write drawbacks of Darwin's theory
Charles Darwin explained the origin of species through ______.
Industrial melanism was highlighted by ______.
