Radicalising this claim, one may argue that epigenetics teaches us something new and valuable about genetics, but it is difficult to see how it could scale up to be the general story of how organisms and environments interact. Instead, Niewöhner argues, we should go beyond both a ‘gene-centric’ and an ‘environment-centric’ approach to identify the particular practices that dynamically shape both environments and genes. Such an approach may trace its pedigree from a long lineage focusing on ‘natural history’, and may ultimately be Aristotelian in the focus on habits (Atran 1993). It argues for a customary biology (Niewöhner 2011), that is, a biology which shifts the analytical focus away from genes and environment to how customs, or patterned practices (Roepstorff et al. 2010), may shape environment and genome. In this understanding, the notions of ‘health’ and ‘environment’ are entangled in a way that moves their relation beyond interdependence to one of inseparability. The subtitle of this volume captures this insight through the concept of ‘health environment’.
‘Health environment’ may, we believe, allow for a fresh analytical perspective on Lock’s notion of local biology. This is beautifully illustrated in Svendsen’s analysis (this volume) of pigs as experimental model animals in a Danish context. Already, the ordinary Danish pig, ‘with leaner meat, an extra rib and large litters’, is an instance of a local biology, which is currently being exported to the rest of the world. The Danish pigs are the result of highly specific practices of breeding based on systematic selection. Underlying mechanisms, most likely not only – if at all – epigenetic, shape the genetic makeup of the pig, and go hand in hand with a specific environment in which the pigs are reared. The general case of the local biology of the Danish pig is taken a step further in the laboratory practices Svendsen studies. Here, the local biology of immature piglets born prematurely by Caesarian section become models of weak infants at risk of potentially devastating inflammation of the gut, thus ideally improving the health of preterm human infants worldwide. Paraphrasing Willerslev, it is the piglet’s status as non-human on the one hand that makes it ethically justifiable to force early birth on the piglets and ultimately kill them, while their existence as non non-humans on the other is the rationale for making them model animals in the first place, so comparable to infants that findings may be generalised from one species to the other (Willerslev 2004).
While this case certainly involves genes and environments in very specific and dynamic configurations, the engine infusing energy into these interactions can be found neither at the level of genes nor of environment. Rather, it is embedded in very particular networks and institutions of power, interest and intentions. Failing to take these into account means failing to identify critical factors shaping both environment and genes.
Scale
The discussion about how to define and delineate the environment also involves questions of scale. Following Niewöhner’s concept of the embedded body (Niewöhner 2011), Lock points out that an epigenetic world (as perceived from an anthropological perspective) is one where ‘recognition of intergenerational continuities other than by the transmission of DNA brings about a crucial ontological shift; an embedded body is not the product of interactions of nature and nurture but, by definition, is situated in an entanglement of nature–nurture that transcends generations, raising profound questions about concepts of self and body as clearly bounded entities’ (Lock 2013, 303). Such permeability of bodies, which had previously been seen as bounded entities, contributes further to undermining the traditional ‘division of labour’ between anthropology and biology. Opening disciplinary boundaries allows us to move beyond the problem of bounded environments to a discussion of scale as a central question of analysis – a need that has appeared in other debates as well, for example, in the context of globalising dynamics (for instance, Collier and Ong 2005; Tsing 2015) and in global health (Adams 2016).
In the context of the present volume, this move can be seen as requiring an extension of anthropology to include reflections on the social life of the bacterial cells living in or on the human body seen as a holobiont (Young, this volume). Young uses the study of the human biome to move us beyond the positions of determinism versus free will as he discusses how bacteria take decisions to create (or not) biofilm, or to send out (or not) into the universe themselves as they are transformed into spores (sporulation) that may eventually mature into biofilm elsewhere. While it is still little understood how gut bacteria communicate bi-directionally with the brain, and what effects this may have on human decision-making processes, moods and behaviours – if, indeed, these should not just be seen as integral – Young points out that bacterial decision making is itself not predetermined. Rather, we should understand quorum-sensing of bacteria as a capacity for stochastic intelligence: ‘During periods of collective stress, such as exposure to antibiotics, a small fraction of individuals become “competent”, able to take up DNA from the environment. Competence is a stochastic function (the result of randomness in transcription) that enables the leader to exploit noise (random variation) generated during quorum-sensing’ (Young, this volume). Scale works at two levels here. One is the qualitative shift incurred by the sheer number of micro organisms, leading to increasing differentiation among them and involving individual decision making; and the other is the shift of analytical scale, relating the behaviour of people accessible to standard ethnographic methods to the behaviour of bacteria in the gut, seen through the lens of (an anthropological reading of) microbiology.
Scale is also important in the analysis of development of multi drug-resistant tuberculosis (MDRTB) by Seeberg (this volume). He compares the stress experienced by Mycobacterium tuberculosis (M. TB) when exposed to anti-tuberculosis medicines to that resulting from attacks by mycobacteriophages, viruses that target tuberculosis (TB) bacteria. The outcome of both kinds of engagement is unpredictable and may be either beneficial or detrimental for the TB bacteria, depending on events at other scales of reality. These include, for example, the life conditions of the host and his or her interaction with family and healthcare providers; the constitution of the healthcare system providing treatment; and decisions of global actors like the Bill and Melinda Gates Foundation to fund technological solutions to be rolled out in contexts that favour budget cuts in government-funded healthcare in low-income countries where TB is rampant. In theory, the combination therapy that has been used for decades should make the development of drug resistance impossible. However, the configuration of actors at very different scales seems to create a situation where M. TB is able to engage with anti-TB drugs in ways similar to its engagements with mycobacteriophages.
The many glitches in drug delivery and global policy priorities create ample opportunity for TB bacteria to make use of their stochastic intelligence. Indeed, even if the intention is to kill them, drug-resistant bacteria may de facto be considered to be domesticated versions of treatable TB, created as they are by human intervention. Hence, one could apply Napier’s phrase: ‘… human selection for tameness is not “natural selection”; it is “human selection” – a social process about creating social environments in which certain genetic traits emerge. As such, it has quite a bit to do with evolution, but as much, or more, with the effects of social environments – including experimental settings – on genetics’ (Napier, this volume). Only, Napier is talking about multi-species interaction at a different scale, namely of domestication through selective breeding of foxes that become dog-like after only a few generations, and subsequently remain ‘dogs’. Napier shows here that social exposure is the key variable that allows genes to function or be shut off. He goes on to discuss another ‘social disease’, namely that of diabetes, where such biosocial dynamics have been largely ignored, globally leading to an over-reliance on biomedical and technical explanations and interventions that are too expensive to access for most people in most countries, while largely ignoring the social dynamics that