Related topics: proceedings of the national academy of sciences , cancer , cells , genes , mutations
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
Wikipedia.
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News tagged with genetic mutations
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 ...
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 ...
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 ...
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.
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 ...
Love hurts: Why emotional pain really affects us
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.
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 ...
Postmortem genetic tests after sudden death may provide less expensive way to identify risk
Nov 15, 2009 |
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Targeted postmortem testing to identify genetic mutations associated with sudden unexplained death (SUD) is an effective and less expensive way to determine risk to relatives than comprehensive cardiac testing of first degree ...
Ancient penguin DNA raises doubts about accuracy of genetic dating techniques
Nov 10, 2009 |
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Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been ...
Researchers Discover Mutations in Two Genes that Cause Early-Onset Inflammatory Bowel Disease
Nov 05, 2009 |
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(PhysOrg.com) -- An international team including researchers with the National Institutes of Health has discovered that mutations in either of two related genes cause a severe and rare form of inflammatory bowel disease (IBD) ...
There's a speed limit to the pace of evolution, biologists say
Nov 02, 2009 |
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Researchers at the University of Pennsylvania have developed a theoretical model that informs the understanding of evolution and determines how quickly an organism will evolve using a catalogue of "evolutionary speed limits." ...
Clinical tests begin on medication to correct Fragile X defect
Medicine & Health / Neuroscience
Nov 02, 2009 |
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NIH-supported scientists at Seaside Therapeutics in Cambridge, Mass., are beginning a clinical trial of a potential medication designed to correct a central neurochemical defect underlying Fragile X syndrome, the most common ...
Genetic links to fungal infection risk identified
Oct 28, 2009 |
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(PhysOrg.com) -- Two genetic mutations that may put individuals at increased risk of fungal infections have been identified by scientists from UCL and Radboud University, increasing understanding about the genetic basis of ...
Ancient bison genetic treasure trove for farmers
Oct 20, 2009 |
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(PhysOrg.com) -- Genetic information from an extinct species of bison preserved in permafrost for thousands of years could help improve modern agricultural livestock and breeding programs, according to University ...
Yale's scan of Turkish infant's genome yields a surprise diagnosis
Oct 19, 2009 |
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(PhysOrg.com) -- In a dramatic illustration of the power of emerging genetic technologies, Yale University researchers have reported making a clinical diagnosis for the first time using comprehensive DNA sequencing of all ...
