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
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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 ...
Of Mutants and Mechanisms: Researching Growth-Regulation Proteins That Underlie Cancer
13 hours ago |
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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 ...
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) ...
Two genes cooperate to cause aggressive leukemia
Nov 03, 2009 |
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Two genes, each one of which is known to cause cancer on its own, together can lead to aggressive leukaemia. This is the conclusion from new research carried out on gene-modified mice at the Sahlgrenska Academy at the University ...
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." ...
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Medicine & Health / Neuroscience
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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 ...
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Soon you could be genetically screened for mitochondrial disorders quickly and comprehensively. Research published in BioMed Central's open access journal, Genome Medicine, outlines an innovative clinical diagnostic test f ...
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Yale's scan of Turkish infant's genome yields a surprise diagnosis
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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 ...
Time in a bottle: Scientists watch evolution unfold
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A 21-year Michigan State University experiment that distills the essence of evolution in laboratory flasks not only demonstrates natural selection at work, but could lead to biotechnology and medical research ...
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Oct 15, 2009 |
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(PhysOrg.com) -- While some scientists have argued that cancer is such a complex genetic disease that you'd have to sequence a person's complete genome in order to predict his or her cancer risk, a University of California, ...
Gene mutation may reveal clues for treating lung diseases
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(PhysOrg.com) -- A genetic mutation found in four children born with multiple abnormalities may provide insight into potential treatments for newborn lung distress and chronic obstructive pulmonary disease (COPD).
Singapore scientists discover widely sought molecular key to understanding p53 tumor suppressor gene
Oct 13, 2009 |
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Scientists at the Singapore Immunology Network (SIgN) have determined how the master gene regulator p53 could switch a gene in a cell "on" or "off" by recognizing specific sequences of nucleotides in the gene's DNA.
