concept

mutation

A mutation is a change in the DNA sequence that can cause disease, affect symmetry, or drive evolutionary processes.
10 related articles

Description

A mutation is a permanent change in the nucleotide sequence (the building blocks of DNA) of DNA, arising from replication errors (DNA duplication), recombination (exchange of segments between chromosomes), or under the influence of mutagens (factors that cause mutations). Point mutations affect a single base pair; their types: substitution (missense — amino acid substitution, nonsense — stop codon appearance), insertion or deletion, often leading to a reading frame shift (alteration of codon grouping). Chromosomal mutations are larger rearrangements: deletions (loss of segments), duplications (doublings), inversions (180° rotation), translocations (relocations). Genomic mutations change the number of chromosomes (aneuploidy — abnormal number, polyploidy — multiplication of the entire set). Mutations can be somatic (in non-reproductive cells, not transmitted) or germinal (in reproductive cells, inherited). Most mutations are neutral or harmful, but in rare cases increase fitness, becoming material for natural selection.

History

The concept of mutations as discrete changes dates back to Hugo de Vries, who in 1901–1903 described them in evening primrose, using the term "mutation" to denote sudden heritable deviations. Thomas Morgan and his school, working with fruit flies in the 1910s, established the connection between mutations and chromosomes. In 1927, Hermann Muller experimentally proved the mutagenic effect of X-rays, laying the foundations of radiation genetics. In the mid-20th century, the discovery of the structure of DNA allowed a transition to molecular understanding of mutations.

How it works

At the molecular level, mutations arise as a result of chemical changes in nucleotides or errors in template synthesis. For example, deamination of cytosine converts it to uracil, which during replication is read as thymine, replacing a C-G pair with T-A. Sources of spontaneous mutations include tautomeric shifts of bases, leading to mispairings during replication. Induced mutations occur after DNA attack by exogenous agents. If the repair system fails, the change becomes fixed in the next replication cycle. Consequences depend on the type of mutation and its location: mutations in promoter regions alter gene expression levels; nonsense mutations truncate the protein; mutations in splice sites disrupt intron removal; epigenetic changes do not affect the DNA sequence but can be heritable. The evolutionary significance of mutations is as the primary source of genetic variation for natural selection.

In practice

Mutations underlie evolution and the diversity of life, and their study helps understand the causes of cancer and create new plant varieties.

Fun fact

In humans, each germ cell carries on average about 100 new mutations not present in the parents, making us all a bit mutant.

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Related articles · 25

q-bio.MN2026-09-112 minarXiv:2609.90025
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q-bio.GN2026-09-072 minarXiv:2609.07500
A Map of Mutation Winds: Where DNA Flows Downhill and Where It Swirls into Eddies
Picture a wind map over a mountain range. The wind mostly blows downhill, following elevation changes. But if you look closely, in some valleys the air swirls into little eddies that keep the wind from simply flowing down. That is exactly what the mutation field in human DNA looks like.
q-bio.TO2026-09-072 minarXiv:2609.90045
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q-bio.GN2026-09-072 minarXiv:2609.07500
A Map of Mutation Winds: Where DNA Flows Downhill and Where It Swirls into Eddies
Picture a wind map over a mountain range. The wind mostly blows downhill, following elevation changes. But if you look closely, in some valleys the air swirls into little eddies that keep the wind from simply flowing down. That is exactly what the mutation field in human DNA looks like.
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A tightly stretched membrane, squeezed into a narrow case, decides on its own where to burst. So does a cell: when it is cramped, the point of division shifts from the middle, and the two halves come out unequal. Previously, it was thought that such asymmetry is predetermined by chemical labels, but the new work shows that mechanics alone is enough.
q-bio.GN2026-08-253 minarXiv:2608.90070
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q-bio.PE2026-07-141 minarXiv:2607.12919express
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q-bio.PE2026-07-131 minarXiv:2607.11011express
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Every tumor writes its own cosmology. Its cells are galaxies, and mutations are stellar flares marking the branches of a genealogical tree. The key to its history is the rhythm of accumulating genetic typos.
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q-bio.PE2026-07-131 minarXiv:2607.11520express
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q-bio.QM2026-07-042 minarXiv:2607.06583express
How Every Cell Ages: A Journey Through the Methylation Landscape
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cs.CG2026-07-014 minarXiv:2607.01046
Monodromy in Vineyards: Blame It on One Singularity
Two passengers step into an empty car on a ring subway line and take their seats. After one full loop, they are surprised to find themselves in each other’s seats — even though nobody moved. That’s pretty much how monodromy plays out in vineyards — families of persistence diagrams, a method rooted in the work of Henri Poincaré.
q-bio.PE2026-06-191 minarXiv:2606.21351express
How Antibodies Learn: A Map of Beneficial Mutations
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q-bio.MN2026-06-151 minarXiv:2606.16803express
How Cell Division Rewrites a Cell's Fate
Inside every cell, a complex network of genes determines what it will become — a nerve cell, a muscle cell, or part of the skin. This choice often resembles flipping a toggle switch: two stable positions, and the cell decides which way to tip. But cells have a feature rarely considered in such models: they divide.
q-bio.GN2026-05-231 minarXiv:2605.24520express
How to Tell a Dangerous Mutation from a Harmless One
In a vast library where each book is a gene, you need to find a single typo. The error might be harmless, or it might completely change the meaning of the sentence. That's roughly what geneticists do when they hunt for harmful mutations among millions of harmless differences. The program, named AnnotateMissense, works like a meticulous proofreader.
q-bio.PE2026-05-052 minarXiv:2605.04339express
The Patchwork Quilt of Evolution
A patchy landscape isn't just a picture from a geography textbook. For microbes, cells, or animals, the world is a mosaic of patches: warmer here, more food there, and behind that rock — almost poison. When a mutant with a new trait appears in such a mosaic, its fate depends on which patch it lands on. This new work ties two factors together.
q-bio.PE2026-04-181 minarXiv:2604.17036express
The Landscape Evolution Wanders Through
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q-bio.PE2026-04-172 minarXiv:2604.16065express
Microbes at the Edge of a Breakdown
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q-bio.PE2026-04-121 minarXiv:2604.10571express
Evolution by the Same Rules
Engineers improving neural networks act like breeders: they try a variant, check the result, and keep the best. They collected 935 such trials from 161 papers and measured how often a code tweak turns out beneficial, harmful, or neutral. The picture is familiar to any biologist: 68% of changes degrade performance, 19% do nothing, and only 13% yield a gain.
q-bio.PE2026-04-111 minarXiv:2604.09966express
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q-bio.QM2026-03-011 minarXiv:2603.02274express
Inside the Cell: How Cancer Dodges the Drug
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q-bio.QM2026-02-221 minarXiv:2602.19295express
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cs.ET2026-01-262 minarXiv:2601.18435express
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q-bio.QM2026-01-172 minarXiv:2601.12101express
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q-bio.GN2026-01-142 minarXiv:2601.09758express
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