Epigenetics is a branch of genetics that studies the factors that do not directly modify our genes (and other living beings), but the way they express themselves. For us to understand, DNA is a very long code that contains everything we are: the color of our eyes, how much hair we have, how a drug affects us, etc.

 

The information that DNA contains is called a genotype and it is the same for all of our cells. However, the expression of that information may be different depending on the cell, the state it is in, or other factors. This expression is called a phenotype. With the same genotype, different characteristics can be observed thanks to the variation of phenotypes. Thus, there are animals that change their fur or color during winter, for example. Or even with age, the way our body reacts changes. However the genetic information will always remain the same until we die. We owe these changes, therefore, to how we express that information (the phenotype). Epigenetics, therefore, studies the way that different expressions are produced and the factors that cause them without directly modifying DNA.