By Rebecca Delker, PhD
Complementarity, born out of quantum theory, is the idea that two different ways of looking at reality can both be true, although not at the same time. In other words, the opposite of a truth is not necessarily a falsehood. The most well known example of this in the physical world is light, which can be both a particle and a wave depending on how we measure it. Fundamentally, this principle allows for, and even encourages, the presence of multiple perspectives to gain knowledge.
This is something I found myself thinking about as I witnessed the twitter feud-turned blog post-turned actual news story (and here) centered around the factuality of physician-scientist Siddhartha Mukherjee’s essay, “Same but Different,” published recently in The New Yorker. Weaving personal stories of his mother and her identical twin sister with experimental evidence, Mukherjee presents the influence of the epigenome – the modifications overlaying the genome – in regulating gene expression. From this perspective, the genome encodes the set of all possible phenotypes, while the epigenome shrinks this set down to one. At the cellular level – where much of the evidence for the influence of epigenetic marks resides – this is demonstrated by the phenomenon that a single genome encodes for the vastly different phenotypes of cells in a multicellular organism. A neuron is different from a lymphocyte, which is different from a skin cell not because their genomes differ but because their transcriptomes (the complete set of genes expressed at any given time) differ. Epigenetic marks play a role here.
While many have problems with the buzzword status of epigenetics and the use of the phrase to explain away the many unknowns in biology (here, here), the central critique of Mukherjee’s essay was the extent to which he emphasized the role of epigenetic mechanisms in gene regulation over other well-characterized players, namely transcription factors – DNA binding proteins that are undeniably critical for gene expression. However, debating whether the well-studied transcription factors or the less well-established epigenetic marks are more important is no different than the classic chicken or egg scenario: impossible to assign order in a hierarchy, let alone separate from one another.
But whether we embrace epigenetics in all of its glory or we couch the term in quotation marks – “epigenetics” – in an attempt to dilute its impact, it is still worth pausing to dissect why a public exchange brimming with such negativity occurred in the first place.
“Humans are a strange lot,” remarked primatologist Frans de Waal. “We have the power to analyze and explore the world around us, yet panic as soon as evidence threatens to violate our expectations” (de Waal, 2016, p.113). This inclination is evident in the above debate, but it also hints at a more ubiquitous theme of the presence of bias stemming from one’s group identity. Though de Waal deals with expectations that cross species lines, even within our own species, group identity plays a powerful role in dictating relationships and guiding one’s perspective on controversial issues. Studies have shown that political identities, for example, can supplant information during decision-making. Pew Surveys reveal that views on the issue of climate change divide sharply along partisan lines. When asked whether humans are at fault for changing climate patterns, a much larger percentage of democrats (66%) than republicans (24%) answered yes; however, when asked what the main contributor of climate change is (CO2), these two groups converged (democrats: 56%, republicans: 58%; taken from Field Notes From a Catastrophe, p. 199-200). This illustrates the potential for a divide between one’s objective understanding of an issue and one’s subjective position on that issue – the latter greatly influenced by the prevailing opinion of their allied group.
Along with group identity is the tendency to eschew uncertainty and nuance, choosing solid footing no matter how shaky the turf, effectively demolishing the middle ground. This tendency has grown stronger in recent years, it seems, likely in response to an increase in the sheer amount of information available. This increased complexity, while important in allowing access to numerous perspectives on an issue, also triggers our innate response to minimize cost during decision-making by taking “cognitive shortcuts” and receiving cues from trusted authorities, including news outlets. This is exacerbated by the rise in the use of social media and shrinking attention spans, which quench our taste for nuance in favor of extremes. The constant awareness of one’s (online) identity in relation to that of a larger group encourages consolidation around these extremes. The result is the transformation of ideas into ideologies and the polarization of the people involved.
These phenomena are evident in the response to Mukherjee’s New Yorker article, but they can be spotted in many other areas of scientific discourse. This, unfortunately, is due in large part to a culture that rewards results, promotes an I-know-the-answer mentality, and encourages its members to adopt a binary vision of the world where there is a right and a wrong answer. Those who critiqued Mukherjee for placing too great an emphasis on the role of epigenetic mechanisms responded by placing the emphasis on transcription factors, trivializing the role of epigenetics. What got lost in this battle of extremes was a discussion of the complementary nature of both sets of discoveries – a discussion that would bridge, rather than divide, generations and perspectives.
While intra-academic squabbles are unproductive, the real danger of arguments fought in absolutes and along group identity lines lays at the interface of science and society. The world we live in is fraught with complex problems, and Science, humanity’s vessel of ingenuity, is called upon to provide clean, definitive solutions. This is an impossible task in many instances as important global challenges are not purely scientific in nature. They each contain a very deep human element. Political, historical, religious, and cultural views act as filters through which information is perceived and function to guide one’s stance on complex issues. When these issues include a scientific angle, confidence in the institution of science as an (trustworthy) authority plays a huge role.
One of the most divisive of such issues is that of genetically modified crops (GMOs). GMOs are crops produced by the introduction or modification of DNA sequence to incorporate a new trait or alter an existing trait. While the debate spans concerns about the safety of GMOs for human health and environmental health to economic concerns over the potential disparate benefits to large agribusiness and small farmers, these details are lost in the conversation. Instead, the debate is reduced to a binary: pro-GMO equals pro-science, anti-GMO equals anti-science. Again, the group to which one identifies, scientists included, plays a tremendous role in determining one’s stance on the issue. Polling public opinion reveals a similar pattern to that of climate change. Even though awareness of genetic engineering in crops has remained constantly low over the years, beliefs that GMOs pose a serious health hazard have increased. What’s worse, these debates treat all GMO crops the same simply because they are produced with the same methodology. While the opposition maintains a blanket disapproval of all engineered crops, the proponents don’t fare better, responding with indiscriminate approval.
Last month The National Academy of Sciences released a comprehensive, 420-page report addressing concerns about GMOs and presenting an analysis of two-decades of research on the subject. While the conclusions drawn largely support the idea that GMOs pose no significant danger for human and environmental health, the authors make certain to address the caveats associated with these conclusions. Though prompted by many to provide the public with “a simple, general, authoritative answer about GE (GMO) crops,” the committee refused to participate in “popular binary arguments.” As important as the scientific analysis is this element of the report, which serves to push the scientific community away from a culture of absolutes. While the evidence at hand shows no cause-and-effect relationship between GMOs and human health problems, for example, our ability to assess this is limited to short-term effects, as well as by our current ability to know what to look for and to develop assays to do so. The presence of these unknowns is a reality in all scientific research and to ignore them, especially with regard to complex societal issues, only serves to strengthen the growing mistrust of science in our community and broaden the divide between people with differing opinions. As one review of the report states, “trust is not built on sweeping decrees.”
GMO crops, though, is only one of many issues of this sort; climate change and vaccine safety, for example, have been similarly fraught. And, unfortunately, our world is promising to get a whole lot more complicated. With the reduced cost of high-throughput DNA sequencing and the relative ease of genome editing, it is becoming possible to modify not just crops, but farmed animals, as well as the wild flora and fauna that we share this planet with. Like the other issues discussed, these are not purely scientific problems. In fact, the rapid rate at which technology is developing creates a scenario in which the science is the easy part; understanding the consequences and the ethics of our actions yields the complications. This is exemplified by the potential use of CRISPR-driven gene drives to eradicate mosquito species that serve as vectors for devastating diseases (malaria, dengue, zika, for example). In 2015, 214 million people were affected by malaria and, of those, approximately half a million died. It is a moral imperative to address this problem, and gene drives (or other genome modification techniques) may be the best solution at this time. But, the situation is much more complex than here-today, gone-tomorrow. For starters, the rise in the prevalence of mosquito-borne diseases has its own complex portfolio, likely involving climate change and human-caused habitat destruction and deforestation. With limited understanding of the interconnectedness of ecosystems, it is challenging to predict the effects of mosquito specicide on the environment or on the rise of new vectors of human disease. And, finally, this issue raises questions of the role of humans on this planet and the ethics of modifying the world around us. The fact is that we are operating within a space replete with unknowns and the path forward is not to ignore these nuances or to approach these problems with an absolutist’s mindset. This only encourages an equal and opposite reaction in others and obliterates all hope of collective insight.
It is becoming ever more common for us to run away from uncertainty and nuance in search of simple truths. It is within the shelter of each of our groups and within the language of absolutes that we convince ourselves these truths can be found; but this is a misconception. Just as embracing complementarity in our understanding of the physical world can lead to greater insight, an awareness that no single approach can necessarily answer our world’s most pressing problems can actually push science and progress forward. When thinking about the relationship of science with society, gaining trust is certainly important but not the only consideration. It is also about cultivating an understanding that in the complex world in which we live there can exist multiple, mutually incompatible truths. It is our job as scientists and as citizens of the world to navigate toward, rather than away from, this terrain to gain a richer understanding of problems and thus best be able to provide a solution. Borrowing the words of physicist Frank Wilczek, “Complementarity is both a feature of physical reality and a lesson in wisdom.”