Название | Biosocial Worlds |
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Автор произведения | Группа авторов |
Жанр | Биология |
Серия | |
Издательство | Биология |
Год выпуска | 0 |
isbn | 9781787358263 |
Environment – nature – is exhibiting all the signs of stress, trauma, toxicity and abuse usually associated with suffering human bodies – the ‘ruins of capitalism’, as Anna Tsing puts it, are all too evident in vast swaths of the globe (Tsing 2015). But geologists need hard evidence of an irreversible transition in order to identify a new epoch. Their decisions are pegged to a so-called ‘golden spike’ – a marker that appears in ice-cores, the oceans, lake sediments, and soils, where recognisable fossilised strata appear that can be hammered, sampled, and/or dug up. Such changes are known as a ‘time-rock unit’. Following much debate, the International Union of Geological Sciences agreed that July 1945 constituted such a spike – the day when the first nuclear device was exploded, leaving rare isotopes of plutonium distributed all over the globe, including Antarctica and Greenland (Biello 2015).
For more than a decade we have been living with another fundamental change known as the ‘post-genomic’ era. The human genome is no longer recognised unequivocally as the driving force of life, but rather as ‘reactive’ to environments external and internal to the body (Gilbert 2003). In other words, the very ‘nature’ of what it is to be human has been revised on the basis of knowledge, largely brought to light when mapping the human genome, with enormous consequences for understanding human development, health, ill-health, and possibly our very survival.
Anthropocenic destruction of the environment and its impact on human wellbeing is not distributed equally worldwide; its effects are scalar. Readily apparent in places such as Dhaka, Bangladesh, where children as young as eight spend their days breathing in toxic fumes produced by leather tanning, in other geographical locations, closer investigation is required to discern how individual genomes everywhere are responding to environmental stimuli affecting health and wellbeing. In April 2017, Greenpeace reported that research has shown that plastic ingested by fish is liable to end up on our dinner plates; plastic pollution in our oceans is now so widespread, it is becoming part of the food chain everywhere.
Behavioural epigenetics
In what follows, I first set out the surprising findings that emerged when mapping the human genome. These discoveries encouraged a burgeoning of research in the field known today as ‘behavioural epigenetics’, a discipline anchored by the impact of environmental variables external and internal to the body on human development throughout the life course, from the moment of conception on. The idea of ‘environment’ is apparently self-evident, so much so that Raymond Williams gave it no entry in Keywords (Williams 1983), although he describes nature, often associated with environment, as ‘perhaps the most complex word in the English language’. According to the Oxford English Dictionary, the earliest definition of the word ‘environment’ appears in the mid-eighteenth century as ‘that which environs’ and also as ‘the objects or the region that surrounds anything’ (Oxford English Dictionary). Contemporary dictionaries include the following meanings: ‘The aggregate of surrounding things, conditions, or influences; milieu, the air, water, minerals, organisms, and all other external factors surrounding and affecting a given organism at any time and, further, the social and cultural forces that shape the life of a person or a population.’ Clearly, if the notion of environment is central to any given scientific endeavour, it requires delineation, demarcation and/or contouring at the outset.
Epigenetics is being heralded as a scientific discipline that may well transcend the reductionism associated with many investigations carried out in the field of molecular genetics. However, several social scientists have expressed concern about the apparent neo-reductionism evident in the majority of projects currently being conducted under the umbrella of environmental epigenetics (Lock 2013a, 2013b; Niewöhner 2011; Richardson 2015). Several of the illustrative examples presented in this paper make it clear that a tendency exists on the part of epigeneticists to systematically scale down and miniaturise what is delineated as environment in their research projects. This practice enables standardisation of methodologies, and makes it possible to carry out all-important replication studies. The result is that economic and socio-political variables that contribute in profound ways to health and illness are set to one side. This is in no way to deny the importance of the molecularlised findings as such, but to suggest that if the implications of these rich insights emerging in epigenetics are to be fully grasped, then limiting accounts to the effects of proximate variables on human bodies falls short.
Epigenetics is slowly exposing certain of the molecular pathways both external and internal to the body by means of which depredating situations literally transform individual genomes; findings such as these are regarded by many scientists and non-scientists as ‘hard’ data, tout court, and such molecular profiles will almost certainly become the first line of evidence to assist in decision making in the courts and by policy makers in connection with neglect, abuse and other forms of violence. The cases discussed below make clear how important it is that documentation of bodily epigenetic changes not be limited to proximate variables. On the contrary, when it comes to medical care, policy making and legal cases, economic and socio-political variables that impact on everyday life that have clearly contributed to the situation should be included. In addition, narratives given by affected individuals furnish invaluable data.
The field of epigenetics is young, and many research findings are at present provisional. Even so, this burgeoning specialty has the potential to bring about a paradigm shift that has already transformed the world of genomics to a considerable extent. Similarly, the fields of epidemiology and public health are undergoing a seismic shift in thinking about nosologies of ill health and early death: the effects of poverty, violence and low levels of education that have long been researched by epidemiologists and public health practitioners can now be linked directly to epigenetic changes that affect brain development and functioning throughout life. Moreover, it is increasingly clear that even if such epigenetic changes are not transmitted intergenerationally they are all too often produced anew in ensuing generations if the social conditions are not changed. Media reporting and social media make it clear that clinicians and the public at large are processing this information, although not always with the required accuracy and precaution that is needed.
The reactive genome
Following the announcements in 2001 that the human genome had been mapped (which was not at that time, strictly speaking, true) many surprises came to light, certain of which scientists had predicted prior to embarking on the Human Genome project (HGP), but that had been ignored. It was revealed that humans have approximately 20,000 genes, and not 100,000 as had been predicted. Numerous plants have many more genes than do humans, and the diminutive worm C. elegans has about the same number as ourselves. The size of a genome bears no relationship to its complexity, and the genome is not a template for the organism as a whole. Only approximately 1.2 per cent of DNA segments actually code for proteins, and the remaining 98.8 per cent was initially labelled disparagingly as ‘junk’ (Gibbs 2003). Given that DNA is among the most non-reactive, chemically inert molecules in the world, with no ‘power to reproduce itself’, as Richard Lewontin puts it (Lewontin 2000, 141), it is somewhat surprising in retrospect that so much significance was attributed to this molecule in the first place.
Non-coding segments of the genome initially appeared to have no obvious function. It soon became evident that they are frequently remnants of bacterial and viral genomes that serve to separate out the coding parts of the genome, thus inhibiting unwanted mutational changes during DNA transmission between generations. Moreover, numerous of these non-coding DNA sequences are highly conserved, implying that they have been present in genomes for hundreds of millions of years, strongly suggesting that they are crucial to both the fundamental processes of life and to evolutionary change.
Furthermore, it is well established that the activities of non-coding RNA (ncRNA) comprise a comprehensive regulatory system that functions to create the ‘architecture’ of organisms, without which chaos would reign. To this end, ncRNA profoundly affects the timing of processes that occur during development, including stem cell maintenance, cell proliferation, apoptosis (programmed cell death), the occurrence of cancer and other complex ailments (Mattick 2004). These findings greatly advanced