The Epigenetics Revolution, How Modern Biology is Rewriting Our Understanding of Genetics, Disease and Inheritance Junk DNA, A Journey Through the Dark Matter of the Genome
Written by Nessa Carey

A New Understanding

Review by Gunnel Minett

When their children go to school, many parents discover that the teaching of certain subjects has changed dramatically since their own school days. Biology is just such a subject. The genome project has opened up whole new areas of research as to what goes on in the cells of all living organisms.

It was in 2000, only 15 years ago, that the entire human genome was first sequenced. At the time, many believed that mapping the genome would enable us to understand the basics of how life evolved. In addition, we would find cures for diseases, such as cancer, and that this would represent a complete turning point for medicine. No surprise then that the success of the genome project led to a frenzy in biological research.

Fairly quickly it became obvious that genes alone could not explain the unique characteristics of human individuals. We simply had too many in common with the most primitive of animals, and even plants, for them to be the final blueprint for human behaviour. The numbers did not add up either; there seemed to be too few human genes to account for our complexity. And genetic determinism failed to explain why or how identical twins could develop in different ways.

One result of this research was that Genetics ‘branched out’ into Epigenetics, the study of cellular and physiological trait variations that are not caused by changes in the DNA sequence. In other words, it is the study of the external or environmental factors that turn genes on or off, controlling where and when genes are expressed.
From assuming that identifying genes would be sufficient to understand how an organism functions, it has become clear that there were more factors involved. The genome constitutes more of a ‘user manual’ that allow an organism to respond to its environment than a rigid set of rules. Epigenetics studies the factors that interact with DNA, which can affect cell development. To start with, focus was on the DNA codes that produce proteins (genes), since proteins are the essential molecular building blocks that underlie all life. The rest was labelled ‘junk DNA’ since it initially did not seem to have a function.

Further studies, however, established that only 2% of the genome codes for proteins. The obvious question was why on earth 98% of our genome should be ‘junk’ with no real function. As Carey explains in her latest book, ‘Junk DNA’, a much more complex scenario is emerging. Although the picture is far from clear yet, it has become obvious that junk DNA is far from ‘junk’. On the contrary, it contributes (in a different way from protein-coding genes) to the intricate system of finely
tuned functions within the cell. Among the characteristics which may depend on ‘junk DNA’ are; our wellbeing, looks and our ability to lead a long and healthy life.
One of the interesting findings to emerge from the field of epigenetics is the hugely important influence of the environment has on gene expression. In the Epigenetics Revolution, Carey gives examples of how environmental factors effected victims of the Dutch famine during WW2. Thanks to good record keeping in the Netherlands, research has shown how this extreme external factor had a huge effect on gene expression pattern of the affect individuals. The period of starvation affected, not just on the generation immediately exposed, but also their children and grandchildren. It also showed that it was not a simple lack of food that had an impact on pregnant women, but also the particular period of their pregnancy at which this occurred. The effects on the victim’s children include a life- long propensity to be underweight (as in the case of the film star Audrey Hepburn).
Stress comes in many forms though, and it is becoming more evident that it is not just the physical environment that can affect gene expression. Psychological stress can also have an effect on cellular activities, highlighted by an exciting new area of psychology that looks at the connection between body and psyche, and the role of emotions in this interaction. Jaak Panksepp’s animal research is a good example of this.*

Although we know from many sources already that our environment is important for our wellbeing, Epigenetics offers a biological mechanisms to help explain how this occurs. For a layperson interested in expanding their knowledge in this growing and fascinating area of research, Nessa Carey’s books offer a very good introduction. The language is accessible and written by someone with in-depth knowledge of this field.

Understanding the basic building blocks of all life also offers food for thought in a number of other areas, from nutrition to psychology through to consciousness studies. Above all it helps us see that we are part of a larger creation of all life on the planet where everything seems to be based on interaction and co-existence. In a wider perspective it could even be said that this adds a spiritual aspect to Epigenetics.

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