Question

Assertion [A]: Evolution is a continuous process that takes millions of years for speciation.
Reason [R]: During evolution only mutation leads to speciation.

• A. Both assertion and reason are incorrect
• B. Assertion is correct but reason is wrong
• C. Both assertion and reason are correct
• D. Assertion is correct and reason explains the assertion

Answer 1

The correct option is B Assertion is correct but reason is wrong

Evolution is a slow and continuous process that takes a very long time to form a new species. Variations in species are caused not only by mutations but could also be due to other processes like genetic drift, gene flow and natural selection. Mutation is the random change in an organism’s genetic makeup which influences the population’s gene pool. In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies in a gene pool. These variations in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes, lead to the phenomenon called genetic drift. Organisms that are better adapted to their environment tend to survive longer and transmit more of their genetic characteristics to succeeding generations than do those that are less well adapted, and this process is called natural selection.