What is the Difference Between Silent and Neutral Mutation

The main difference between silent and neutral mutation is that silent mutation is a specific type of neutral mutation that does not have any observable effect on the phenotype of an organism, whereas neutral mutation is a mutation (change in DNA sequence) that is neither beneficial nor harmful to the survival or the reproduction of an organism.

A mutation is a change in the DNA sequence of an organism. Sometimes, mutations can pass on to descendants during reproduction. The mutations that are passed on to the next generation are called germline mutations, while mutations that are not passed to the next generation are known as somatic mutations. Mutations occur due to DNA replication errors during cell division and exposure to mutagens or viral infections. It’s interesting to note that mutations frequently occur in our bodies. But most mutations do not persist long as our cells recognize these mutations and quickly repair them. Some mutations are beneficial, some are harmful, and some are neither beneficial nor harmful to the organisms. In fact, mutations are identified as a critical contributor to the process of evolution. Furthermore, there are many types of mutations, including germline mutations, chromosomal alternations, point mutations, and frameshift mutations.

Key Areas Covered

1. What is a Silent Mutation
      – Definition, Features, Effects
2. What is a Neutral Mutation
      – Definition, Features, Effects
3. Relationship Between Silent and Neutral Mutation
      – Outline of Common Features
4. Difference Between Silent and Neutral Mutation
      – Comparison of Key Differences

Key Terms

Silent Mutation, Neutral Mutation

Difference Between Silent and Neutral Mutation  - Comparison Summary

What is a Silent Mutation

Silent mutations are mutations in DNA that do not have an observable effect on the phenotype of an organism. They are a type of neutral mutation. Silent mutations occur when a change of a single DNA nucleotide within a protein-coding part of the gene does not affect the sequence of amino acids that make up the protein of the gene. In silent mutations, there is a change in one of the bases in the triplet bases (codons). This is possible due to the degeneracy of the genetic code. Silent mutations are also a type of point mutation.

Compare Silent and Neutral Mutation - What's the difference?

Furthermore, silent mutations can be either base substitutions, deletions, or insertions. For example, consider the codon AAA. In a silent mutation, G is substituted, and the codon becomes AAG. But both AAA and AAG codons specify the amino acid lysine. Hence, the amino acid sequence remains the same.

Silent mutations are considered not that important. But they might help in creating genetic diversity among the species in a population. Changes that the triplet code is subjected to can cause changes in the protein translation efficiency, timing, and rate of protein folding, leading to functional impairments. Sometimes, silent mutations can also cause mental disorders.

What is a Neutral Mutation

A neutral mutation is a type of mutation that is neither beneficial nor harmful to the organism in survival and reproduction. In population genetics, neutral mutations refer to mutations that do not have any impact on the way natural selection affects the spread of the mutation in a population. It is a genetic alternation whose phenotypic expression does not change the adaptive value or the fitness of an organism.

Neutral mutations that are not associated with any genes under selection or that can be inherited are subject to a process called genetic drift. This process involves random sampling of alleles within a population, which can lead to either the fixation or loss of a particular allele. In the case of neutral mutations, this means that they have an equal chance of either being lost or replacing all other alleles of a given gene in the population.

Relationship Between Silent and Neutral Mutation

  • Both silent and neutral mutations are two types of mutations.
  • Both these mutations do not have an observable effect on the organism’s phenotype.
  • All silent mutations are neutral mutations, but not all neutral mutations are silent mutations.

Difference Between Silent and Neutral Mutation

Definition

A silent mutation is a type of neutral mutation that does not have any observable effect on the phenotype of an organism, whereas a neutral mutation is a mutation that is neither beneficial nor harmful to the survival or the reproduction of an organism.

Changing the Amino Acid Sequence

Silent mutations do not change the amino acid sequence, whereas neutral mutations change the amino acid sequence.

Affecting the Fitness of the Organism

Since silent mutations cause changes in the protein translation efficiency, timing, and rate of protein folding and lead to functional impairments, they can affect an organism’s fitness. However, neutral mutations do not change an organism’s adaptive value or fitness.

Conclusion

 A mutation is a change in the DNA sequence of an organism. There are many types of mutations, and silent mutations and neutral mutations are two of them. The main difference between silent and neutral mutation is that silent mutation is a specific type of neutral mutation that does not have any observable effect on the phenotype of an organism, whereas neutral mutation is a mutation (change in DNA sequence) that is neither beneficial nor harmful to the survival or the reproduction of an organism.

Reference:

1. “Silent mutation.” Biology Online.
2. “Neutral Mutations.” Study Smarter.

Image Courtesy:

1. “Different Types of Mutations” By Jonsta247 (CC BY-SA 4.0) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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