Epigenetics Overview

Epigenetics Overview

Darwin coined that evolutionary change be due in part to genetic variation and heritability. The concept of passing genes to a future generation and changes in the genetic sequence, are typically understood as occurring within the genotype and thus DNA sequence. Genetics refers to the gene sequence within our chromosomes, on contrary epigenetics is other factors that control gene expression. Epigenetics is the study of cellular and trait variations that do not occur because of a change in the DNA sequence and cause heritable changes in gene expression. In short, epigenetics investigates changes in the phenotype without a change in the genotype. Both DNA methylation and histone modification have been noted as mechanisms that result in epigenetic change since the modification does not affect the DNA sequence. These modifications determine how much or whether a gene is expressed in your body. Since these epigenetic changes are heritable, they can also impact evolution.  

Prior to roughly 1970, it was widely believed that certain behaviors or choices were not heritable to future generations, although that has been disproven through epigenetic studies. For example, a person that smokes and overeats could pass that epigenetic information to their offspring. Some epigenetic information is lost and replaced with different information to the future generation, although some may remain. Therefore that person who smokes and overeats may only pass on the trait of smoking, while the trait of overeating was lost. This is all due to which genes are expressed through epigenetics. The DNA methylation may "turn on" particular genes or the histone may contract to hide particular pieces of DNA. 

This implies that behaviors or occurrences in the parents' environment could drastically affect the genetic expression of their children. Studying epigenetics can help our understanding of gene expression and how to regulate gene expression. This understanding could lead to scientists silencing epigenetic expression of unfavorable genes such as those that could lead to cancers. It also implies that our DNA (genetic material itself) is not the only factor of "who we are" and that environment does play a key role in gene expression. Epigenetics is a new field of study that will impact future generations and potentially enhance their lives.