Question

The theory of Natural Selection dwells on:
(a) Role of environment in evolution
(b) Natural selection acting on favorable variations
(c) Changes in gene complex resulting heritable variations
(d) Inheritance of acquired characters

Answer 1

Hint: The theory of natural selection was given by Charles Darwin and Alfred Wallace. The theory explains the evolution of species on the basis of natural selection. Nature selects the organism with the characters that are most suited for the environment it is living in.

Complete Step by Step Answer:
The theory of natural selection dwells on natural selection acting on favorable variations. In simple words, we can explain this by saying the survival of the fittest. When there are variations in organisms of a species, some variations would prove more useful than others. The organisms with those useful variations have a better chance of survival and reproduction. So, as they reproduce better, their offsprings will be more in number and will have inherited these useful variations as well.

So, the correct option is (B), ‘Natural selection acting on favorable variations’.

Additional information: Let us discuss the theory of natural selection in detail.
According to Darwin, the strongest or intelligent species was not the one selected by nature. But instead, the species most responsive to change and getting adapted to the changes in the environment will be selected.
For evolution to take place properly, there should be a large number of populations of a species existing. This will ensure many kinds of variations to be present. Now the variations with the most advantage will be picked by nature. With time only the members with the advantageous variations will be left and after a few million years such variations get accumulated and give rise to a new species.

Note:
- Darwin researched his theory in the Galapagos Islands where he studied Darwin’s finches.
- Alfred Wallace came to a similar understanding based on his research in South America and East Asia.
- Hugo de Vries came up with the mutation theory which suggested evolution takes place because of a large mutation and not many variations accumulating overtime.