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.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with mutations
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 ...
Study shows that some malignant tumors can be shut down after all
Nov 09, 2009 |
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Oncologists have had their hands tied because more than half of all human cancers have mutations that disable a protein called p53. As a critical anti-cancer watchdog, p53 masterminds several cancer-fighting operations within ...
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 ...
Researchers find a weak link in cancer cell armor
Nov 11, 2009 |
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(PhysOrg.com) -- Professor Robert Weiss has found that when two particular genes are inhibited, cancer cells are destroyed at a greater rate. The study is published in the Nov. 9 issue of PNAS.
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.
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.
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) ...
New cause of osteoporosis: Mutation in a miroRNA
Nov 16, 2009 |
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Many biological processes are controlled by small molecules known as microRNAs, which work by suppressing the expression of specific sets of genes. Xiang-Hang Luo and colleagues, at Second Xiangya Hospital of Central South ...
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 ...
Of Mutants and Mechanisms: Researching Growth-Regulation Proteins That Underlie Cancer
Nov 09, 2009 |
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(PhysOrg.com) --A University of Arkansas researcher will study potential cancer-causing mutants of a protein involved in cell growth regulation, thanks to a supplemental grant from the National Institutes ...
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 ...
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.
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.
