The Evolving World of Epigenetics

Written by Sarah | December 12, 2020 | Science

Introduction to the Epigenome

The argument of nature vs. nurture has been going on for over 50 years. What affects our behavior and personality most? Is it our nature (our genetics and heredity) or our nurture (the environment we live in and the experiences we have)?

Identical twins make prime test subjects since they have identical genetic makeup. Thus, studies have been conducted in which twins were separated at birth and made to live different lives to record the effects on their behavior and personality. The results weren’t very surprising. As it turns out, genetic makeup triumphs over environmental influence for certain factors such as IQ; however, environmental influences triumph over genetics in other cases, such as depression. Therefore, we can assume that nature and nurture play fairly equal roles in our lives.

But what about identical twins that are not separated at birth and grow up in very similar – if not the same – environments? Do they not display very different behaviors and personalities from time to time? Then, if their natures are identical, and their nurture nearly so, how do we explain this disparity?

That’s where epigenetics comes into play.

Epigenetics is that missing factor between nature and nurture that determines our personalities, behaviors and even our predisposition to illnesses and disease. Then, the question must be posed, what exactly is epigenetics?

What Is Epigenetics?

The word epigenetics can be interpreted as, “in addition to changes in genetic sequence,” which, in essence, is exactly what it is. The field of epigenetics focuses not on genes themselves, but rather on the ability – or inability – of a gene to express itself through the existence of epigenetic marks.

Epigenetic marks are little chemical tags that attach themselves either directly to DNA (deoxyribonucleic acid) or histones (large proteins about which DNA is tightly wound), and the influence they have on our genes is immense. These little chemical tags work as a sort of switch for our genes; they can turn off or turn on a gene based on the enzymes that created them.

The enzymes that form epigenetic marks are often created by lifestyle choices that you – or the generations before you – have made, and they can be inherited from your parents before conception and/or during pregnancy. You can even develop new marks during the course of your lifetime.

The Influence of Epigenetic Marks

We now understand what epigenetics and epigenetic marks are, but how do they influence us in the world outside of our genes?

The answer to that is every single way you could possibly imagine!

Our genes play an incredibly large part in determining who we are. Passed down from our parents, genes can determine our physical qualities, such as eye and hair color, our personality traits, such as whether or not we are an extrovert or introvert, and even our predisposition to disease and illness, like cancer or addiction.

In short, genes affect nearly every aspect of our lives, in one way or another. Because epigenetic marks can turn a gene on or off, that means they can also impact our lives in ways that were not anticipated as per our genetic makeup.

Let’s say, for example, that both your parents passed down the dominant gene for blue eyes to you. In the sensible world of genetics, you’d be expected to come into the world with beaming bright blue eyes just like your parents. However, when you were in the womb, an epigenetic mark tagged itself onto your gene for blue eyes and turned it off, leaving the gene for brown eyes on and functional. Therefore, instead of having blue eyes like your parents, you come into the world with brown eyes. This is just one very simple example of the effect that epigenetic marks can have on you as an individual.

Why Epigenetics Is Important

As we’ve previously established, epigenetic marks can turn a gene on and off, eliciting certain characteristics while stifling others. This information helps us better understand what is happening in our bodies and what determines who we are. Nevertheless, how can we put this information into use? Why is the study of epigenetics so critical to our society and well-being?

Similarly to the example of blue eyes I gave earlier, epigenetic marks can have the same effect on genes that influence our health, such as anti-cancer genes and oncogenes (genes that mutate healthy cells into cancerous ones). Epigenetic marks have the ability to turn off anti-cancer genes and turn on oncogenes, thereby making a person more susceptible to cancer, or to turn on anti-cancer genes and turn off oncogenes, making a person less susceptible to cancer and allowing the body to fight off existing cancer much easier.

Scientists have noticed this capability of epigenetic marks, and they believe that they can take advantage of it by generating certain enzymes that are likely to produce epigenetic marks that turn off oncogenes and turn on (or increase the production of) anti-cancer genes to treat cancer patients. This discovery is incredibly promising, and with further research into epigenetics and the growth of our ability to influence epigenetic marks, the prospect of a healthier society is closer than ever.

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