The key difference between silent and neutral mutation is that silent mutation is a specific type of neutral mutation that does not have an observable effect on the organism’s phenotype while neutral mutation is a change in the DNA sequence that is neither beneficial nor harmful to the ability of an organism to survive and reproduce.
A mutation is a change that occurs in the nucleotide sequence of DNA. Mutation can take place due to environmental factors like cigarette smoke and UV light or due to viral attacks, strong chemicals, etc. Mutations in the germline cells pass into the next generations while mutations in the non-germ cells (somatic mutations) do not pass into the next generations, and they will affect a single organism’s survival. Silent mutations do not result in changes in the amino acid sequence of the encoded protein. Neutral mutations do not cause an observable effect on the organism’s phenotype.
CONTENTS
1. Overview and Key Difference
2. What is Silent Mutation
3. What is Neutral Mutation
4. Similarities Between Silent and Neutral Mutation
5. Side by Side Comparison – Silent vs Neutral Mutation in Tabular Form
6. Summary
What is Silent Mutation?
Figure 01: Types of Mutations
A silent mutation is a type of mutation that does not cause changes in the amino acid sequence of the encoded protein. Therefore, silent mutations do not alter the amino acid sequence. Generally, silent mutations change one of the bases in the triplet bases (codons). In spite of the single base change, the amino acid that is coded by that particular codon remains unchanged. This is possible due to the degeneracy of the genetic code. Silent mutations can be base substitutions, insertions or deletions.
An example of silent mutation is the substitution of G for the codon AAA. When G is substituted, codon becomes AAG. However, both AAA and AAG codons specify the amino acid lysine. Therefore, the amino acid sequence remains unchanged.
Silent mutations were considered to be of little or no significance. However, silent mutations can be beneficial in creating genetic diversity among species in a population. The alterations to the triplet code can cause changes in protein translation efficiency and timing and rate of protein folding leading to functional impairments. Silent mutations can also cause mental disorders.
What is Neutral Mutation?
A neutral mutation is a type of mutation that is neither beneficial nor detrimental. According to population genetics, neutral mutations are mutations that are not affected by natural selection. In fact, it is a genetic alteration whose phenotypic expression does not change the organism’s adaptive value or fitness. Moreover, neutral mutations become a part of the neutral theory of molecular evolution. Neutral theory states most variation at the molecular level do not affect the fitness of the organism. Since neutral mutations are not affected by the natural selection, their fate is driven by genetic drift.
What are the Similarities Between Silent and Neutral Mutation?
- Silent and neutral mutations are two types of mutations.
- Both types of mutations do not cause an observable effect on the organism’s phenotype.
What is the Difference Between Silent and Neutral Mutation?
Silent mutation is a mutation that does not change the amino acids sequence of the encoded protein. Neutral mutation, on the other hand, is a mutation that has no observable effect on the organism’s fitness. This is the key difference between silent and neutral mutation.
The following infographic summarizes the difference between silent and neutral mutation.
Summary – Silent vs Neutral Mutation
A mutation is a change in the nucleotide sequence of DNA. Some mutations are heritable and passed to the next generations. Moreover, some mutations cause genetic diseases. However, some mutations do not change the phenotype and do not cause any harm. Silent mutation and neutral mutation are such types of mutations that do not cause an observable effect on the organism’s phenotype. Silent mutations do not change the amino acid sequence of the protein. Neutral mutations are not beneficial or detrimental. Silent mutations are a specific type of neutral mutation. Thus, this is the summary of the difference between silent and neutral mutation.