Epigenetics: an end to the ‘nature-nurture’ debate!

After the discovery of the DNA structure by Watson and Crick, and the evidence that every DNA is unique to the extent that the matching probability of a calculated DNA profile stands one in a billion, whoever thought that the way a human think and perceives can alter the working of our genes? Yes, the human body and mind are intricate and with the increasing amounts of research have come some unexpected results. Epigenetics is one such area of study that focuses on changes in DNA that do not involve alterations to the underlying sequence. In other words, epigenetics explains how cells control gene activity without changing the DNA sequence. The subject area is challenging as it aims to explain how the cells behave differently despite being made from the same set of the genes. It has long puzzled scientists why there are differences between identical twins, despite having the same inherited DNA.

Throughout our lifespan, the cognitive functions of the brain adapt to the environment by remaining flexible and responsive. It is in direct communication with the outside world; constantly giving and receiving signals. One of the most important functions of the brain is to store memories and learn from experiences. “Many brain functions are accompanied at the cellular level by changes in gene expression. Epigenetic mechanisms such as histone modification and DNA methylation stabilize gene expression, which is important for long-term storage of information.” (https://learn.genetics.utah.edu/content/epigenetics/brain).

In practical terms, the research has shown that exposure to certain experiences eg famine, smoking, stress has an impact on an individual, not just ‘psychologically’ but in fact via ‘switching on’ certain genes, which remain switched off in others who were not exposed in this way.

Several studies conducted on mice shows us the gene known as “agouti” if methylated gives brown color to the mice, and yellow if unmethylated. Research conducted on humans whose ancestors survived famines in Sweden and Netherlands helps us understand the effects of starvation on epigenetics, which can last for three generations. “Nutrient deprivation in a recent ancestor seems to prime the body for diabetes and cardiovascular problems, a response that may have evolved to mitigate the effects of any future famines in the same geographic area.” (Hybrids, Super Soldiers & the Coming Genetic Apocalypse Vol.1, Volume 1)

Epigenetics has challenged our previous knowledge of inheritance which claimed that the inheritances only pass through the DNA code from the parent to the offspring. Today, thanks to the discovery of epigenetics, it can be seen that ‘nurture’ ie the experiences of a human (or other mammal) within its lifetime, also affects genetic expression and can be passed to future generations.’ At last, the nature – nurture debate has been settled, as both nature (the DNA inherited) and nurture (epigenetics) have an impact on how a person develops, and indeed on what is passed on to the next generation.

Citations:

Guardian News and Media. (2014, April 25). Epigenetics 101: A beginner's guide to explaining everything | cath ennis. The Guardian. Retrieved April 29, 2023, from https://www.theguardian.com/science/occams-corner/2014/apr/25/epigenetics-beginners-guide-to-everything