Nature vs Nurture Answered – Nurture Is Shown To Affect Our DNA
Can the things we experience in life leave a mark on our DNA? This idea has captured the imaginations of many and is incredibly popular in today’s media. For example, the entire premise of the Assassin’s Creed series is that memories leave a mark on and are passed down through DNA, allowing the ordinary Desmond Miles to relive the adventures of his Assassin ancestors. And while we probably won’t be able to explore the memories of our ancestors in real life, there actually is a scientific basis behind the idea that our DNA can be modified after birth, holding important psychological and physiological consequences that would greatly impact our lives.Before going on, here are some simple concepts:DNA – “the building blocks of life”, DNA is like an instruction manual on how to build a human. It is in the form of long sequences which forms the famous double helix structure.Gene – genes are particular sections of DNA that has instructions on how to make one particular protein. Much like a chapter in an instruction manual, they hold instructions on how to make one specific component.DNA methylation – a chemical change to our DNA which changes the way it is read by our body. This doesn’t change the sequence; it’s more like an on/off switch for particular genes.Proteins – the body’s machinery to perform certain tasks such as digest food or maintain our body. Proteins are the outcome of DNA. Childhood experiences could affect us at a genetic level. In the past decade, the age old question of nature versus nurtured has been answered by epigenetics. It turns out that experiences in our childhood may alter our DNA. What this means is that nurture might also change nature; not only change emotionally, but we also change physically.Scientifically, this subject has been called “behaviour epigentics” and is one of the hottest topics in this decade. The experiment that started this off was the examination of rats brought up in different environments. Some rat mothers would nurture their pups by licking and grooming them; whilst others would mostly ignore their pups. Rats that were raised by negligent mothers were found to be more sensitive to stress (so if you grew up in a nurturing environment you might cope with stress better). The response to stress was measured chemically via the detection of cortistorne (a hormone – chemical messenger that is sent throughout the body).The scientists proposed that this is due to the reduced number of glucocorticoid receptors (a protein that is expressed in DNA) these rats had and this is in turn attributed to methylation in the DNA. Hence different upbringings that rats experience are correlated with in DNA expression.How this experiment relates to human beings has been a topic of great scientific debate. Important questions such as the long term effects of childhood abuse have been proposed and examined. Initial findings suggested an increased amount of DNA methylation. However, as with all things relating to humans, experimental evidence is much harder to obtain and hence it is much more difficult to provide a concrete answer.Environmental consequences Epigenetics effects could also be caused by major events for an example a major famine. One well know example is that children that have survived a famine have a increased risk for obesity. It was found that children who have been directly affected by a famine had less DNA methylation compared to same family siblings who were not directly starved. Epigenetics caused by environmental factors have also been used to explain why identical twins (who have the same DNA) might develop different diseases.Although a lot could be attributed to environmental epigenetic factors, its often overused to explain too many issues. This is because its nearly impossible to directly attribute one event to one effect, human beings are very complicated species and thus its almost aways a chain of events that cause certain effects. What makes environmental epigenetics difficult to research is that there simply aren’t that many large disasters in the world (thank goodness for that!) and thus located and research people effected by them is difficult.Conclusion
To conclude, one could picture our DNA as a book and this book can have different meanings depending on what pages you read. The methylation of DNA (epigenetics) controls what pages of our book is read and hence we might become different people even if we have the same DNA. If the experiments prove to be true, then one could hypothetically make a machine that would look at DNA, more specifically where it is methylated and find out a bit about our childhood upbringing or major events we have been through. Unfortunately, whether we could relive our ancestor’s memories might be a far stretch as DNA methylation doesn’t change our genetic sequence and hence isn’t very readily passed to the next generation.
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