Related topics: cancer , genes , protein , genetic mutations , evolution
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
Time in a bottle: Scientists watch evolution unfold
Oct 18, 2009 |
4.6 / 5 (42) |
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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 ...
Natural selection may not produce the best organisms
Biology /
Jul 18, 2008 |
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"Survival of the fittest" is the catch phrase of evolution by natural selection. While natural selection favors the most fit organisms around, evolutionary biologists have long wondered whether this leads to the best possible ...
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 ...
How Did Evolution Begin?
Sep 28, 2009 |
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(PhysOrg.com) -- Life's ability to replicate itself is essential for evolution, yet even the simplest kind of replication requires a relatively complex system. So what kind of non-replicating system might ...
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 ...
Large reservoir of mitochondrial DNA mutations identified in humans
Aug 11, 2008 |
4.6 / 5 (20) |
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Researchers at the University of Newcastle, England, and the Virginia Bioinformatics Institute at Virginia Tech in the United States have revealed a large reservoir of mitochondrial DNA mutations present in the general population. ...
Natural selection is not the only process that drives evolution
Biology /
Jan 27, 2009 |
4.3 / 5 (21) |
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Why have some of our genes evolved rapidly? It is widely believed that Darwinian natural selection is responsible, but research led by a group at Uppsala University, suggests that a separate neutral (nonadaptive) process ...
Cancer patient genome sequenced for the first time
Nov 05, 2008 |
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For the first time, scientists have decoded the complete DNA of a cancer patient and traced her disease - acute myelogenous leukemia - to its genetic roots. A large research team at the Genome Sequencing Center ...
Survival of the fittest: even cancer cells follow the laws of evolution
Biology /
Aug 01, 2008 |
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Scientists from The Institute of Advanced Studies at Princeton and the University of California discovered that the underlying process in tumor formation is the same as for life itself—evolution. After analyzing a half million ...
Professor sequences his entire genome at low cost, with small team
Aug 10, 2009 |
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(PhysOrg.com) -- The first few times that scientists mapped out all the DNA in a human being in 2001, each effort cost hundreds of millions of dollars and involved more than 250 people. Even last year, when ...
In Ocean's Depths, Heat-Loving 'Extremophile' Evolves a Strange Molecular Trick
Apr 30, 2009 |
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(PhysOrg.com) -- Making its home near extreme temperatures of thermal vents on the ocean floor, the organism Methanopyrus kandleri harbors a molecular secret that intrigues evolutionary biologists and even ...
Common mutations linked to common obesity in Europeans
Jul 07, 2008 |
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Scientists have discovered two common genetic mutations in people of European ancestry, which affect the production of several hormones controlling our appetite. The mutations have a significant effect on ...
Modern life's pressures may be hastening human evolution
Apr 13, 2009 |
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We're not finished yet. Even today, scientists say that human beings are continuing to evolve as our genes respond to rapid changes in the world around us. In fact, the pressures of modern life may be speeding up the pace ...
Scientists find new genes linked to lung cancer
Oct 22, 2008 |
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Working as part of a multi-institutional collaboration, scientists at Washington University School of Medicine in St. Louis have assembled the most complete catalog to date of the genetic changes underlying the most common ...
Scientists crack gene code of common cancers
Dec 17, 2009 |
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Two common forms of cancer have been genetically mapped for the first time, British scientists announced, in a major breakthrough in understanding the diseases.
