Epigenetics: How the environment modifies genes

Key Definitions: Genotype, Phenotype, and Epigenetics

In order to understand the complex interplay between heredity and environment, it is crucial to define three concepts that are absolutely fundamental to this field of study.

Genotype refers to a person's complete genetic makeup, which contains all of their characteristics, both those that are expressed and those that are not.

Phenotype, on the other hand, corresponds to the characteristics that are observable in a person, that is, the physical manifestation of their genetic makeup.

Finally, epigenetics is the mechanism that has the ability to turn genes on or off, thus determining the functions that cells will have.

Epigenetics focuses on chemical modifications that do not alter DNA, but rather influence gene activity and how they are expressed.

Early Experiences and Their Impact on DNA

During development, the DNA that as our genes accumulate a series of chemical markers that determine how much they will be expressed.

New scientific research has shown that environmental influences can directly affect whether and how genes are expressed.

The different experiences that children have, especially in the early stages, have the power to rearrange these important chemical marks in their genes.

These epigenetic signatures, which can be both temporary and permanent, determine how easily genes will be activated or deactivated.

In this way, the environment in which a person develops before and after birth provides experiences that alter the genes that were inherited.

The Explanation of the Differences in Identical Twins

The field of epigenetics offers us a clear explanation of why twins who are genetically identical can come to exhibit different behaviors.

Although they share the same DNA sequence, the different life experiences that each one has accumulate different chemical markers in their respective genomes.

It is precisely this difference in "epigenetic signatures" that means the same gene can be activated in one twin and remain inactive in the other.

As a result of this different genetic expression, twins can develop different skills, have different health, and even achieve different milestones in life.

The Susceptibility of the Epigenome to Influences

The epigenome is not only naturally modified to guide development, but it is also susceptible to the influence of environmental factors such as toxins.

The prefix "epi" means "above" or "on," illustrating how these modifications act above the DNA sequence without directly changing it.

Positive experiences, such as supportive relationships, as well as negative ones, such as stress, leave a unique epigenetic signature on a person's genes.

This knowledge completely refutes old ideas that genes are engraved in stone or that alone determine the development of an individual.