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Adaptive mutation, also called directed mutation or directed mutagenesis is a controversial evolutionary theory. It posits that mutations, or genetic changes, are much less random and more purposeful than traditional evolution, implying that organisms can respond to environmental stresses by directing mutations to certain genes or areas of the genome.
The role of epigenetics in evolution is clearly linked to the selective pressures that regulate that process. As organisms leave offspring that are best suited to their environment, environmental stresses change DNA gene expression that is further passed down to their offspring, allowing for them also to better thrive in their environment.
But as an extreme example, if the mutation rate is too high then all individuals will be dead or at least carry a heavy mutation load. Short-term selection for low variation most of the time is likely to be more powerful than long-term selection for evolvability, making it difficult for natural selection to cause the evolution of evolvability.
Although mutations that cause changes in protein sequences can be harmful to an organism, on occasions the effect may be positive in a given environment. In this case, the mutation may enable the mutant organism to withstand particular environmental stresses better than wild-type organisms, or reproduce more quickly.
There are several methods, or forms, of mutation that exist including spontaneous mutation, errors during replication and repair, as well as mutation due to environmental effects. [8] These origins of mutations can cause many different types of mutations which influence gene expression on both large and small scales. [8]
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
Environmental epigenetics is a branch of epigenetics that studies the influence of external environmental factors on the gene expression of a developing embryo. [1] The way that genes are expressed may be passed down from parent to offspring through epigenetic modifications, although environmental influences do not alter the genome itself.
Evolution is the change in a heritable trait in a population across generations since mutations generate variations in the heritable traits; they are considered the raw material for evolution. Therefore, beneficial mutation accumulations during the developmental processes could generate more phenotypic variations, which increases their gene ...