"There are no depths. Appearance is the summary of phenomena."
—Joseph Brodsky
Life on Earth is a narrative written by the deoxyribonucleic acid (DNA). The chemical design of DNA is uniform among every form of life, but its sequence is different between species and individuals. DNA sequences are comprised of millions of differentially combined chemical letters (A, T, C & G) and yield most of the current diversity of species, as well as offering an endless blueprint for the future design of life forms. Once established, life forms tend to stay within the borders of their species, one generation after the other. However, no two individual organisms, even twins, manage to follow precisely the same script. The reason for this is the so called “epigenetic” impact that expands the boundaries of the DNA language and generates another level of diversity by incorporating life experience in its different forms.
What is epigenetics? In the mid-1960s, a founder of epigenetics Conrad Waddington wrote: “Some years ago [in 1947] I introduced the word ‘epigenetics’, derived from the Aristotelian word ‘epigenesis,’ which had more or less passed into disuse, as a suitable name for the branch of biology which studies the causal interactions between genes and their products which bring the phenotype into being.” “Epi” means “upon” or “over,” and “genetics” implies that genes are involved, so the term reflected the need to study events “over” or beyond the gene.
What is beyond, or over the gene? The DNA of a single human cell is 1.2 meters long and is tightly packed within the micron-size cell nucleus. The packed ball of DNA string has a levitating 3D structure where the different strings overlap and loop around each other like folded fishing line. Each loop contains genes that encode proteins as well as numerous regulatory elements that define the gene activity.. Epigenetics addresses the mechanisms that define gene activity without interfering with the gene structure. Thus epigenetics is more a censorship of the DNA “reading” than an editing of the text.
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