Mutations in living entities are referred to as the modification in the genetic information of an organism. These alterations occur spontaneously if there is an error while copying DNA or if the sequence of DNA comes in contact with a kind of mutagen. Mutagens are the agents causing mutations. These mutagens can be chemicals or x-ray radiations.
Factors Affecting Mutation
The overall effect a change in the DNA(mutation) can have on an individual is dependant on certain factors and can have one of these three outcomes:
- No effect
- Positive effect
- Negative effect
Deleterious or harmful mutations can cause serious problems and are termed as a genetic disorder. These mutations can be in the form of genes against the natural selection process, making survival difficult. On the other hand, mutations that cause no change are referred to as neutral mutations that can occur in the part of DNA that is not translated into proteins or the change may occur in the redundant sequence of DNA. Amino acids which are coded for by the DNA, most of them have various sequences that code for them. If a mutation is brought about in one nucleotide base pair that yet codes for the very same amino acid, such a mutation will not affect the organism and is the called the neutral mutation. Beneficial mutations are the ones which have a positive effect on an individual and are referred to as adaptations.
The new structure may help the organism in some way. Beneficial and deleterious mutations affect evolution. Deleterious mutations are harmful and often causes the death of an individual before they reproduce and pass on their genes. This will cause a reduction in the gene pool and hence traits to disappear over a few generations. Beneficial mutations, on the other hand, can give rise to new structures which can help one to survive, as natural selection would be in favour of these traits which can be passed on safely to the next generation. Mutations that occur in the body cells without being passed to the next generation are referred to as a somatic mutation. Germ-line mutations impact the next generation as they occur in the germ cell permitting the change to become prominent over time.
Mutations are essential to evolution as every genetic characteristic in every entity was originally the outcome of mutation. These newly formed genetic variants are passed while reproduction and differential reproduction is a determining aspect of evolution. Mutations permit entities to grow, feed, reproduce with more efficiency causing the mutant allele to spread across with time, producing an eventual change in the phenotype of a population. Deleterious mutations too cause evident evolutionary changes in a small population by eliminating entities that may potentially be carrying adaptive alleles at other genes. Hence mutations that affect the survival of the next generations are agents of evolution. Discover more about mutations and related topics, by registering at BYJU’S.