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  2. Mutation - Wikipedia

    en.wikipedia.org/wiki/Mutation

    In genetics, it is sometimes useful to classify mutations as either harmful or beneficial (or neutral): A harmful, or deleterious, mutation decreases the fitness of the organism. Many, but not all mutations in essential genes are harmful (if a mutation does not change the amino acid sequence in an essential protein, it is harmless in most cases ...

  3. Negative selection (natural selection) - Wikipedia

    en.wikipedia.org/wiki/Negative_selection...

    This can result in stabilising selection through the purging of deleterious genetic polymorphisms that arise through random mutations. [2] [3] Purging of deleterious alleles can be achieved on the population genetics level, with as little as a single point mutation being the unit of selection. In such a case, carriers of the harmful point ...

  4. Muller's ratchet - Wikipedia

    en.wikipedia.org/wiki/Muller's_ratchet

    Illustration of chromosome crossover during genetic recombination. In evolutionary genetics, Muller's ratchet (named after Hermann Joseph Muller, by analogy with a ratchet effect) is a process which, in the absence of recombination (especially in an asexual population), results in an accumulation of irreversible deleterious mutations.

  5. Modifications (genetics) - Wikipedia

    en.wikipedia.org/wiki/Modifications_(genetics)

    Sickle cell disease: In a healthy individual, the HBB gene is responsible for encoding hemoglobin which carries oxygen throughout the body. [16] However, when a person has this disease due to inheriting two mutated copies of the HBB gene due to a base pair point mutation, their red blood cells are shaped differently. [ 16 ]

  6. Mutation rate - Wikipedia

    en.wikipedia.org/wiki/Mutation_rate

    The human germline mutation rate is approximately 0.5×10 −9 per basepair per year. [1] In genetics, the mutation rate is the frequency of new mutations in a single gene, nucleotide sequence, or organism over time. [2] Mutation rates are not constant and are not limited to a single type of mutation; there are many different types of mutations.

  7. Point mutation - Wikipedia

    en.wikipedia.org/wiki/Point_mutation

    Point germline mutations can lead to beneficial as well as harmful traits or diseases. This leads to adaptations based on the environment where the organism lives. An advantageous mutation can create an advantage for that organism and lead to the trait's being passed down from generation to generation, improving and benefiting the entire ...

  8. Deletion (genetics) - Wikipedia

    en.wikipedia.org/wiki/Deletion_(genetics)

    In genetics, a deletion (also called gene deletion, deficiency, or deletion mutation) (sign: Δ) is a mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. [1]

  9. Deformity - Wikipedia

    en.wikipedia.org/wiki/Deformity

    Genetic mutation; Growth or hormone disorders; Skin disorders; Reconstructive surgery following a severe injury, e.g. burn injury; Deformity can occur in all organisms: Frogs can be mutated due to Ribeiroia infection. Plants can undergo irreversible cell deformation [1] Insects, such as honeybees, can be affected by deformed wing virus