Mutation
hideIn biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.
Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.
Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.
Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.
For more information about Mutation, read the full article at
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News tagged with mutations
Lung cancer and melanoma laid bare: First comprehensive analysis of two cancer genomes
Dec 16, 2009 |
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Research teams led by the Wellcome Trust Sanger Institute announce the first comprehensive analyses of cancer genomes. All cancers are caused by mutations in the DNA of cancer cells which are acquired during a person's lifetime. ...
Scientists use DNA sequencing to attack lung cancer
Dec 16, 2009 |
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Aided by next-generation DNA sequencing technology, an international team of researchers has gained insights into how more than 60 carcinogens associated with cigarette smoke bind to and chemically modify human DNA, ultimately ...
Evolution may take giant leaps
Dec 11, 2009 |
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(PhysOrg.com) -- A new study of thousands of species of plants and animals suggests new species may arise from rare events instead of through an accumulation of small changes made in response to changes in ...
Gene identified as cause of some forms of intellectual disability
Dec 15, 2009 |
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A gene involved in some forms of intellectual disability has been identified by scientists at the Centre for Addiction and Mental Health (CAMH), as published this month in The American Journal of Human Genetics. The gene i ...
Genetic studies reveal new causes of severe obesity in childhood
Dec 06, 2009 |
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Scientists in Cambridge have discovered that the loss of a key segment of DNA can lead to severe childhood obesity. This is the first study to show that this kind of genetic alteration can cause obesity. The results are published ...
Umbilical stem cells may help recover lost vision for those with corneal disease
Dec 08, 2009 |
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(PhysOrg.com) -- New research from the University of Cincinnati (UC) may help in the recovery of lost vision for patients with corneal scarring.
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Medicine & Health / Psychology & Psychiatry
Dec 03, 2009 |
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Have you ever felt overly upset by a social snubbing? Your genetics, not your friends, may be at fault.
Netherlands reports mutant swine flu death
Dec 03, 2009 |
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Dutch authorities said Thursday a patient infected by a mutant strain of the swine flu virus had died, but added that this was not the cause of death.
Mutation found in swine flu virus: WHO
Nov 20, 2009 |
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The World Health Organisation said Friday that a mutation had been found in samples of the swine flu virus taken following the first two deaths from the pandemic in Norway.
Combination therapy with midostaurin improves survival of AML patients with FLT3 mutations, phase 1
Dec 08, 2009 |
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A targeted drug that is active against acute myeloid leukemia (AML) is particularly effective when teamed with chemotherapy in patients whose cancer cells harbor a key genetic mutation, researchers at Dana-Farber Cancer Institute ...
New research helps explain why bird flu has not caused a pandemic
Nov 19, 2009 |
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(PhysOrg.com) -- Bird flu viruses would have to make at least two simultaneous genetic mutations before they could be transmitted readily from human to human, according to research published today in PLoS ON ...
For the first time, scientists discover causative gene of a rare disorder by exome sequencing
Nov 17, 2009 |
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(PhysOrg.com) -- UW researchers have successfully used a method called exome sequencing to quickly discover a previously unknown gene responsible for a rare disorder. The finding demonstrates the usefulness ...
China reports 8 cases of mutated swine flu virus
Nov 25, 2009 |
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(AP) -- China has detected eight people infected with mutated forms of the swine flu virus, a health official said Wednesday, but flu drugs and vaccines still work against it.
