A field combining sociology, as well as both genetics and neuroscience, epigenetics is revolutionary as a field in itself. Not only does it have implications on the foundations and evolution of society itself, but it draws on these components too.
We detect the world around us with our sense of smell. Olfaction, far from a mundane sense, enables the detection of food, predators or even mates, making it a primal sense. It is the central sensory modality by which most organisms communicate with their environment, and is therefore a pivotal sensation of interest. What’s more, thanks to the work of scientists such as Richard Axel himself, the vast number of different odors humans can perceive is represented on an extremely well-defined olfactory image - one that can be studied with high precision. Due to its evolutionary significance, the nose is like a portal to understanding enigmas such as innate behaviour, since what, afterall, makes an odor innate and why do we have such an innately configured representation of the sensory world?
One emerging field that studies the relationship between the environment and genetics is epigenetics. Epigenetics literally means “above genes”, and it describes how certain molecules are “turned on” and “off” by certain molecules that attach to them, namely epigenetic markers. Our DNA is one, whether in a skin cell or a nerve cell, but the reasons why cells lead entirely different lives is due to the silencing of particular genes (let’s call this “methylation”). Cells are usually stripped of methylation in the single-celled embryo, and gradually reestablish the methylation as the cell grows and divides. This suggests that while methylation over the course of our own lifetimes can shape our genetic expression, our children remain untouched. However, observing trends, fostered by research into different populations in unique environments, suggests there may be more to the story. What if some epigenetic markers withstood the initial pruning in the embryonic stages? What if embryos were not truly blank slates? Maybe traces of Lamarck’s theory are being revived from the scientific graveyard.
As Virginia Hughes voices in her article “The Sins of the Father”, another question comes to the fore when one thinks of parents’ genetic legacy. How do the effects of our environments become embedded in an animal’s germ cells in the first place? For example, studies have shown that there are differences in microRNA between sperm of men who do smoke and men who do not. There seem to be “somehow” involved when one jumps from the parents phenotype being inherited by the child, but how this is done on a biological level is, in many ways, a black box.
Epigenetics holds tantalizing possibilities for the study of human health and disease. This all may sound intuitive - obviously we inherit traits from our ancestors, but experiences are supposed to rot with the individual. Experiences such as the Dutch Hunger Winter, a terrible time when the Germans cut off all food shipments to dutch citizens in the northwest section of Netherlands, impacted up to 6 generations of descendants. The descendants of mother who were in early stages of pregnancy during this time supposedly have fewer epigenetic markers attached to their IGF2 genes, a gene essential for growth and development before birth, compared to their siblings, and to those whose mothers were in the late stages of pregnancy during the famine. This means that many years after an unfortunate experience, adults whose mothers were exposed at just the wrong time of pregnancy carried the mark of the dutch hunger winter attached to their DNA. There are many other studies that point to a similar mechanism, ones covering intense periods such as the Holocaust or slavery in America.
As one can imagine, there is a lot of pushback, and I do not believe that anyone can with confidence make any grand claims; however, what we do find here is, what Richard Axel calls a “Fascinoma”- something fascinating, ever growing in charm, that merits further investigation.
,