Science has changed so much, exponentially in fact, in the last few years. Things that we had thought were concrete, established facts are being systematically dismantled with new discoveries and proofs. For example, when I was studying, all the textbooks said heart and nerve muscles cannot be regenerated. Superman Christopher Reeve spent his fortune trying to prove that wrong after severing his spinal cord in a riding accident. I didn’t quite believe my cardiologist when he said he could regenerate my heart muscles, because my old textbooks told me they couldn’t. My father-in-law died with only 17% of his heart muscles functioning – his heart was slowly dying on him.
The latest, hottest area of research is epigenetics. Can we really change our genes? We have been brought up to believe that we start with half our chromosomes from mum, and half from dad. This makes the first cell that divides trillions of times to become us, photocopying the original copy again and again. If the copying process goes wrong, we are stuck with it for life. If we inherit a ‘bad’ one from a parent, we are stuck with it for life too.
“My genes made me like this!” That’s what my son Kit use to howl whenever we told him off for being naughty, greedy, loud or boisterous.
From my upcoming textbook on Chemistry:
It has long been established that we cannot change genes. What is, is. But a new branch of science, called epigenetics, has emerged. It is now known that though we cannot change our genes per se, everything we do has the potential to cause chemical modifications around the genes and these changes have the power to switch the genes on or off over time. What you eat, where you live, who you interact with, when you sleep, how you exercise, etc., can have an epigenetic effect on your overall life. Thus, though two movies could start off with an identical script, the directors (or epigenetics factors) can produce two very different landscapes and life experiences indeed based on how the actors and actresses in the movies are directed.
In molecular terms, this is how epigenetics works: it is the molecular mechanisms that affect the activity of your genes. Your lifestyle, you experiences and even your thoughts affect your internal environment, causing a certain reactions to take place. This is no different from turning up the heat on a beaker of reagents or adding a few drops of catalyst to a test-tube to effect certain reactions. These changes within the cells could bring on two main activity paths. The main one involves small methyl molecules getting attached to segments of the DNA (DNA methylation). There are proteins in the cells that are attracted to the methyl groups, that seeks out these methyl groups, bind on to them and effectively shutting down the genes in the region.
The proteins that wrap themselves around the genes that scientists had, in the past, discarded, also play a part in epigenetics. Molecular tags, similar to the methyl groups, get attached to different locations on the histones, bringing about different outcomes. This process is called histone modification and represents the second main pathways that change DNA activity without mutating the DNA itself. Thus, same DNA still, but read differently and resulting in real-life changes.
Perhaps this is the best answer we will ever get for the nature versus nurture question; when we come down to the level of molecules, we see the beautiful interplay between the living being and its environment. Just as an inherited set of ‘perfect’ genes can be degraded by how life is lived, so too can imperfections be reprieved. In this dynamic living world, there always exists the option for good. Live well, eat well, and make every day count for how you live today could change the legacies that we once never thought was impossible. Genetic determinism? Not anymore. We can orchestrate the molecules by the choices we make, from our diet, environment, and sleep patterns to the books we read, the people we spend our lives with. This translocation between molecules and life stories shows that chemistry is truly, deeply the science of life.
My small book on theoretical physics is available on Kindle. Click here.