Epigenetics refers to the process in which DNA can express itself differently at various times, depending on a possible variety of factors. DNA influences how new cells are formed when it is transcribed into RNA, which then becomes proteins that direct cell behavior (Bird, 2007) All cells have the same genetic code, which is DNA; DNA functions therefore as a recipe of sorts. However, not all DNA is activated at the same time; instead, different subsets of DNA instructions are used by different types of cells, which explains how muscle cells develop differently than skin cells or any other type of cell: only the instructions relating specifically to muscle development are used. Epigenetics refers to how cells might receive instructions differently, either through mutation, or perhaps by being exposed to an external, environmental element (Tollefsbol, 2017). Toxins, for instance, might trigger different cell reactions based on reading different instruction sets.

Epigenetics can therefore help explain why identical twins may have different health outcomes despite similar behaviors. Although the two would share identical DNA, this DNA over time may express itself differently in each twin. This might result in behavioral changes, or purely physical changes, depending on where the differentiation occurs.

The implication of epigenetics for human populations is that functions of DNA can potentially be influenced to express themselves in different ways. This has both negative and positive potential; on one hand, epigenetics can be harmful if a gene expresses itself in a way that proves to be malignant. The expression of a gene triggered by a toxic environmental element can be harmful to the individual, and could cause a cascade of mutations (Feinberg and Fallin, 2015). However, if favorable gene expressions can be targeted by physicians, there are a number of potential health benefits. For instance, certain disorders that are believed to have a genetic component, such as obesity (Van Dijk et al., 2015), may be linked to a certain gene expression, or alternatively a lack of gene expression where one would normally function. By targeting this process, physicians may be able to turn these expressions on or off, depending on the desired goal. If a patient whose DNA is not expressing itself correctly can have this problem fixed, then the health problem might be healed. However, there is also the possibility that more than health problems might be targeted by physicians; for instance, certain behaviors or conditions might be favored as well. This raises potential ethical issues, such as with parents who might seek to artificially influence the DNA expression of an unborn child.

The implication of epigenetics for bacterial populations is that bacteria DNA can similarly be altered. However, this can lead to numerous iterations of bacterial strains that if left unchecked, can potentially cause widespread problems. Epigenetics might result in thriving bacterial populations that become resistant to antibiotics, so this poses a significant health risk. Understanding how epigenetic processes work can help develop more effective cures, treatments, or antibiotics to deal with this resistant bacteria, but unfortunately, the same science can also introduce epigenetic elements in an attempt to weaponize the bacteria and create biological weapons.

The science of epigenetics therefore examines how DNA can essentially be manipulated. Although the genetic code in each cell is identical, if certain parts of DNA can be targeted to be turned off or on, there are a wide range of implications; on one hand, there is great potential benefit to science and medicine, but on the other hand, there are potential ethical issues that might be raised. Biological weapons remains one potential danger, but epigenetics also might create a culture of genetic selection, where certain qualities or traits are manipulated by artificially altering the DNA process.