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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.
Epigenetic mechanisms. In biology, epigenetics is the study of heritable traits, or a stable change of cell function, that happen without changes to the DNA sequence. [1] The Greek prefix epi-(ἐπι-"over, outside of, around") in epigenetics implies features that are "on top of" or "in addition to" the traditional (DNA sequence based) genetic mechanism of inheritance. [2]
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.
In 2022, the most comprehensive study of pharmaceutical pollution of the world's rivers found that it threatens "environmental and/or human health in more than a quarter of the studied locations". It investigated 1,052 sampling sites along 258 rivers in 104 countries, representing the river pollution of 470 million people.
There are mechanisms by which environmental exposures induce epigenetic changes by affecting regulation and gene expression. Four general categories of epigenetic modification are known. self-sustaining metabolic loops, in which an mRNA or protein product of a gene stimulates transcription of the gene; e.g. Wor1 gene in Candida albicans;
Evolutionary mismatch can occur any time an organism is exposed to an environment that does not resemble the typical environment the organism adapted in. Due to human influences, such as global warming and habitat destruction, the environment is changing very rapidly for many organisms, leading to numerous cases of evolutionary mismatch.
For niche construction to affect evolution it must satisfy three criteria: 1) the organism must significantly modify environmental conditions, 2) these modifications must influence one or more selection pressures on a recipient organism, and 3) there must be an evolutionary response in at least one recipient population caused by the environmental modification.
The second is the notion of branching evolution, implying the common descent of all species of living things on earth from a single unique origin." [11] Additionally, "Darwin further noted that evolution must be gradual, with no major breaks or discontinuities. Finally, he reasoned that the mechanism of evolution was natural selection." [11]