DNA, the deoxyribonucleic oracle, has been widely heralded as determining your biological future. Your destiny is governed by some microscopic nucleic acids merely sitting in some puny cells in the massive body. It is disheartening to think this way. But does it truly come down to chance in heredity?

Consider the following scenario: a litter of rat pups with the exact same set of DNA is divided into two groups and raised under starkly different mothers. Group A rat babies have the luxury of being groomed by an attentive mother. In the next cage over, Group B pups are left to sit dejectedly in the corner, ignored by their mother who just wants to catch some Z’s. Cycle years forward, when these rats are now adults. Scientists will examine each group’s hippocampus, where GR genes, a type of gene that produces a protein that helps the body relax, are located. It turns out that the Group A test subjects possess active GR genes and have grown to be healthy, calm rats, whereas Group B rats grew anxious, with their dormant GR genes.

Oddly enough, although the DNA sequences in these rats have not changed, they grew up to be very different individuals. There was clearly a correlation between the amount of nurture and number of GR genes present in the hippocampus. The cause of these changes must have been above the genes, and this turns out to be the result of epigenetics. Epigenetics is a relatively new field of science, referring to the heritable modifications of gene expression. In layman’s terms, picture a musical score. The notes on the sheet, dynamics, vibrato, or articulation serve as the epigenetic processes because they affect the ways in which the notes (genes) are expressed, instead of actually messing with the melody itself.

DNA methylation, an epigenetic mechanism, was the reason for the differences in the behavior of the rats from groups A and B. Even though the rats had the same genes, their different upbringings affected whether some genes were active or not. A generous amount of motherly love released brain chemicals that activate cells signaling pathways that remove methyl groups from the DNA and activate the GR gene. For the rats that didn’t receive nurturing, it was as if they were traumatized, molecularly scarred for life.

So why should you bother to care about some pesky rodents? These studies demonstrate that genetics are not only a product of heredity, but also of the environment, which also applies to humans. Epigenetic changes could be passed down from parent to child, one generation after the next. Environmental factors like diet, smoking, stress or exercise can place “tags” on our genes.  This genetic discovery could potentially improve memory, cure cancer, or even speed up metabolism. Epigenetic research has proven that the nature versus nurture battle is far from an end: Both factors play a role in changing a person and his or her offspring.

So maybe before you make reckless decisions followed by a half-baked declaration of YOLO, you could consider the epigenetic consequences. It’s true, you only live once, but your DNA continues to thrive through the generations, along with those epigenetic markers.

Sources: Sciencedaily.com; discovermagazine.com; learn.genetics.utah.edu