49. On admixture methods in general, see Pathak, “Identifying Admixture”; Nathan K. Schaefer, Beth Shapiro, and Richard E. Green, “Detecting Hybridization Using Ancient DNA,” Molecular Ecology 25, no. 11 (2016): 2398–2412.
50. Pathak, “Identifying Admixture,” 13.
51. Pathak, “Identifying Admixture,” 5–20.
52. Pickrell and Prichard, “Inference of Population Splits,” 9, 13.
53. Mark Lipson, “Applying f4-Statistics and Admixture Graphs: Theory and Examples,” Molecular Ecology Resources 20, no. 6 (2020): 1664.
54. See Lipson, “Applying f4-Statistics,” 1666.
55. Éadaoin Harney et al., “Assessing the Performance of QpAdm: A Statistical Tool for Studying Population Admixture,” Genetics 217, no. 4 (2021): 1–17.
56. Harney et al., “Assessing the Performance of QpAdm,” 13.
57. Joseph K. Pickrell and David Reich, “Toward a New History and Geography of Human Genes Informed by Ancient DNA,” Trends in Genetics 30, no. 9 (2014): 382–383.
58. Loog, “Sometimes Hidden,” 4.
59. See Elsbeth Bösl, Doing Ancient DNA: Zur Wissenschaftsgeschichte der aDNA-Forschung (Bielefeld: transcript Verlag, 2017).
3 Past Pathogens and Precarious Futures
Venla Oikkonen
Over the past decades, ancient DNA (aDNA) has emerged as a culturally appealing means of reimagining the connection between the past and the present. In public discussions, aDNA research is often portrayed as providing a material, indisputable link to a prehistoric time. Such a portrayal is based on the idea that aDNA constitutes a fixed, immutable entity that can be unveiled through scientific observation to tell stories about how we became “us.”1 For example, genetic ancestry tests that promise to trace customers’ “Neanderthal” or “Denisovan” ancestry,2 or excited media portrayals of aDNA sequences retrieved from hominin remains,3 seek to root us in a particular version of the past that may be at odds with knowledge produced within archaeological research, communal tradition, or traditional family genealogy.4 Importantly, the presumed genetic connection between the past and the present is also understood to be shaping the very contours of the future through, for example, communities and identities that have emerged around geneticized belonging.5 While the apparent naturalness of aDNA as a means of belonging has been challenged by scholars noting that paleogenomic knowledge relies on choices of datasets, methods, and statistical models, aDNA remains a highly appealing, affectively invested object in cultural discourse.6
However, hominin and animal aDNA is not the only type of genetic material that has fueled discussion about how the distant past shapes the present. This chapter turns to another type of ancient genetic material—that of past pathogens—to understand the role of aDNA as a means of imagining trajectories between the past, present, and future. Pathogens are biological entities able to cause disease. They include, for example, bacteria and viruses. Most pathogens contain some type of genetic material, yet there are also crucial differences in their organization and functioning. For example, bacteria can multiply on their own, whereas viruses require a host cell to replicate.
When frozen past pathogens are thawed, some of them can, at least hypothetically, be reactivated and cause disease. Pathogen aDNA thus carries a capacity that human or animal aDNA lacks, as the latter cannot spontaneously come “alive” and become a new living organism. Yet, notably, traces of ancient pathogens are often discovered while analyzing hominin and animal aDNA from old remains.7 Archaeological and paleontological sites are therefore increasingly seen as a potential source of not only hominin and animal aDNA, but also pathogen aDNA.
Like aDNA from early hominin remains, discovered pathogen aDNA has received considerable public attention. However, whereas the former has mostly garnered fascination, past pathogen discoveries have invoked concerns. Cultural anxieties around past pathogens focus on the perceived liveliness of pathogens as material entities. Such anxieties center on the idea that the genetic material in past pathogens is essentially different from contemporary pathogens and, in the right circumstances, might give rise to reemerging illness. In other words, past pathogens are represented as being potentially able to spontaneously shape our destinies and to hold the future a prisoner of the past. Understanding how past pathogens are conceptualized in culture and science thus complicates the current popular understanding of aDNA as simply telling the story of our genetically rooted belonging. The temporal trajectories between the past, present, and future imagined through aDNA from pathogens are structured by affective tensions and societal concerns that are not typically present in cultural portrayals of hominin aDNA as a genetic document from the past.
Cultural representations of past pathogens center on a particular context: permafrost, ground that is frozen throughout the year for several consecutive years. In cultural discourse and popular science, permafrost is often portrayed as nature’s “freezer” because it has emerged as a source of very old biological material that would not have survived in warmer temperatures. Crucially, this freezer is thawing with climate change, thereby exposing old biological material. With cases such as “Ötzi the Iceman,” whose 5,000-year-old remains were discovered in melting ice in the Alps in 1991,8 or the 2010 reconstruction of the first ancient human genome from 4,000-year-old hair found in permafrost in Greenland,9 permafrost has increasingly been seen as a gateway to previously unknown evolutionary history and early population movement. At the same time, researchers have retrieved traces of deadly pathogens, such as those causing bubonic plague or smallpox, as well as previously unknown viruses and microbes, in the melting permafrost.10 These examples suggest that past pathogens emerging from permafrost not only are sources of knowledge, but may also in some cases constitute potentially viable entities. This is reflected in how past pathogens buried in permafrost are often portrayed as sharing a likeness with refrigerated viral and bacterial samples stored in a microbiology lab.
The idea of an unknown viral or microbial threat lurking in melting permafrost is present in both scientific and public discourse. For example, the review article “Future Threat from the Past” by medical researchers Amr El-Sayed and Mohamed Kamel posits remains buried in permafrost as objects of particular concern for the future of human life.11 The authors reflect on the revival of “Bacillus sphaericus and Staphylococcus succinus … from 25 to 40 million-year-old Dominican amber.” Other articles highlight the urgency of the issue while noting that little is known about whether old microbial and viral material released from permafrost ground constitutes a direct risk to human health and in what circumstances such risk might materialize.12 Concerns about the vitality of emerging pathogens are echoed in media stories, such as the 2017 article “There Are Diseases Hidden in Ice, and They Are Waking Up,” originally published on the BBC’s website. It describes how “permafrost soil is the perfect place for bacteria to remain alive for very long periods of time, perhaps as long as a million years,” which means that “melting ice could potentially open a Pandora’s box of diseases.”13 In a similar vein, a Scientific American article called “Deep Frozen Arctic Microbes Are Waking Up” highlights the unpredictability of dormant pathogens, warning that “organisms that co-evolved within now-extinct ecosystems … may also emerge and interact with our modern environment in entirely novel ways.”14
In this chapter, I locate a key tension at the heart of cultural and technoscientific visions of how past pathogens in permafrost may shape the future. The chapter engages with two cases: an unexpected anthrax outbreak in Siberia in 2016 and the reconstruction of the 1918 pandemic influenza virus. The cases demonstrate two different potentialities. In the first one (anthrax), the past unexpectedly takes over the present; in the second one (pandemic influenza), the past is drawn on to prepare for future pandemics. These differences make visible the ambiguous role of past biological material in the societal search for future health. I will draw from materials ranging from bioscientific articles to media texts and popular science articles on discoveries of past pathogens in permafrost. These materials shed light on how past pathogens and pathogen aDNA discoveries are shaping the ways in which the connection between the past, present and future is imagined in contemporary society.
The Cryopolitics of Pathogens and Permafrost
Old pathogens and aDNA emerging from permafrost are part of the larger politics of freezing and thawing life. Such politics have been called “cryopolitics,” a term coined by historian Michael Bravo and physicist Gareth Rees.15 Science and technology studies scholars Joanna Radin and Emma Kowal have developed the concept further to address technologies and practices of freezing and thawing in biomedicine and science.16 They approach frozen life as “latent life,” a liminal state in which biological matter is neither alive nor dead, yet may—in suitable conditions—come alive.17 This conceptualization of cold temperature, time, and liminality helps to shed light on how past pathogens and their genetic material, when emerging from the frozen ground, are perceived to carry a potentiality to shape the future. Radin and Kowal highlight that cryopolitics centers on the indeterminacy of that future.18 In the case of pathogens and permafrost, the link between what has been and what will be is largely unknown, heightening the affective stakes of permafrost discoveries. Old pathogens may, or may not, engender illness or death.
Different practices and technologies of freezing and thawing life have been discussed widely in science and technology studies as well as other social sciences in recent years.19 The emergence of past pathogens from permafrost resonates with practices of freezing and thawing life-giving entities such as blood, eggs, sperm, embryos, and plant seeds. Like these entities, bacteria and viruses carry the potentiality of generating or shaping life. Yet, there is a crucial difference: the awakening of latent life emerging from permafrost is in itself not a technoscientific, controlled event—although it may result from human action responsible for warming climates. Rather, the melting of permafrost triggers the need for technoscientific intervention, such as public health management and genetic sequencing, including potential manipulation of the retrieved genetic material to create means of managing future diseases.
The cryopolitics of frozen pathogens is embedded in the cryopolitics of permafrost. Permafrost is not just any ice or cold. It is entangled with complex histories and the politics of place and difference. Writing in the context of the North American Arctic, anthropologist Jennifer Hamilton notes that arctic cold has been seen in a popular evolutionary framework as a symbol of a lack of civilization as well as a resource to be exploited by capitalist systems outside the Arctic, for example as a source of frozen meat.20 In such histories, Hamilton notes, cold is associated with often stereotypical perceptions about Indigenous people living in the Arctic, with the result that cold temperatures have long been seen as a rationale for imperialism and settler colonialism. This colonialist logic is repeated in the long history of portraying the Arctic region and its Indigenous populations—both present and past communities—as a particularly important source of contemporary and ancient DNA through which scientists could presumably access human evolutionary history.21 Paying attention to this popular association between indigeneity and cold is crucial in order to understand how ideas of pasts and futures are invoked and reinforced in cultural discourses around the two cases analyzed in this chapter. In both cases, the popular association between indigeneity and cold structures, for example, what kind of technoscientific interventions are perceived as necessary to prepare for and prevent future epidemics. Rooted in the colonialist logic, the association of cold and indigeneity also reinforces a sense of “otherness” and danger around Arctic communities and environments, as old pathogens are portrayed in popular discourse as lying in wait.
Finally, permafrost is also materially distinct from other forms of ice and cold. Landscape architecture scholar Leena Cho traces the emergence of permafrost “as an idea” through the development of US permafrost science and engineering.22 Cho notes that permafrost as a material entity is “active, generative and vibrant,” as it is continuously reshaped through changes in temperature.23 Permafrost’s vibrancy also arises from its mixture of organic and inorganic materials: as a place “where various things across earth’s time—including ancient microbes, hydrocarbons, roots, toxins, scientific probes and building foundations—have been accumulated, separated and reconstituted,” permafrost is unpredictable in its local melting patterns.24 Permafrost, then, is plural, situated and entangled with other ecologies and infrastructures.
Revisiting the concept of cryopolitics, Michael Bravo highlights this vibrancy, noting how ice that has built up slowly over years can thin remarkably quickly within a few months.25 Yet, the futures that may emerge from melting permafrost are not without limits. For example, Bravo explains, there may be no point of return: “The thin layer at the top of permafrost can slowly melt and refreeze annually, but when a critical threshold of permafrost melt takes place it collapses and does not regain its structure when refrozen.”26 Crucially, such thresholds shape whether and when forms of potential life—microbes, viruses, and genetic material—may emerge from organic matter such as remains buried in permafrost. This sense of unpredictability adds to the feeling of danger associated with past pathogens in cultural discourse.
The 2016 Anthrax Outbreak in Siberia
In July 2016, a local anthrax outbreak took place in the Yamalo-Nenets autonomous district in Siberia. A twelve-year-old boy died, dozens of people from the nomadic herding community were affected, and over 2,000 reindeer died of illness. The cause of the outbreak has been linked to the summer heatwave, which had reached 35 degrees Celsius, and the subsequent thawing of permafrost, as well as to longer-term patterns of climate change.27 It was widely suggested at the time that the unusual heat had exposed a reindeer carcass preserved from the previous anthrax outbreak in the region in 1941. It thus appears that anthrax spores had survived seventy-five years in permafrost without losing their capacity to infect organisms.28
The 2016 anthrax outbreak raised considerable international interest. Part of this attention likely arose from the affectively charged cultural association between anthrax and bioterrorism—an association cemented in cultural discourse through the anthrax attacks that took place in the United States in 2001, shortly after 9/11. However, considerable attention focused on permafrost and climate change. Commentators asked: If there were large numbers of cattle burial sites in Siberia and other Arctic areas and the climate kept getting warmer, would there be regular anthrax outbreaks in such regions in the future? What other pathogens lay dormant in permafrost that could awaken like anthrax? These themes were repeated across the media. For example, an article on the website of National Public Radio (NPR) in the United States concluded: “The question for researchers is: Could these pathogens—like anthrax—ever be reactivated?”29 A piece in Scientific American on the anthrax outbreak referred to how “the zombie microbes lurking in the permafrost” are “unknowable and unpredictable in their timing and ferocity,”30 and a news article in the Barents Observer was titled “Scientist: Yamal Anthrax Outbreak Could Just Be the Beginning.”31 Likewise, the Disease Daily website noted that the case “raises questions about the potential impact of climate change on other pathogens suspended in the ice,” as, for example, “smallpox and bubonic plague are also likely embedded in the Siberian ice.”32 Media and other cultural responses, then, extended beyond the case itself to look at the larger issue of melting permafrost. As a result, the anthrax spores released from the ice emerged as symbolic of all old pathogens presumably preserved in the frozen ground.
Much of the coverage of the 2016 anthrax outbreak portrayed the permafrost as a freezer. In the NPR piece mentioned above, for instance, environmental virologist Jean-Michel Claverie described the permafrost soil in the Yamal region as “a giant freezer” that provided “very, very good conditions for bacteria to remain alive for a very long time.”33 This framing connects the reindeer carcass exposed from the melting Siberian permafrost to larger cryopolitics, in which cold temperatures are manipulated to extend life, for example, by freezing embryos for future use.
However, the 2016 anthrax case differs from this technoscientific framework in a crucial way: the freezing and thawing of decades-old animal carcasses is beyond the immediate control of human actors. The media coverage of the 2016 anthrax outbreak clearly demonstrates the affective intensities that accompany this unpredictability. For example, an article in the Washington Post based on an account by a University of Missouri scientist describes how anthrax spores “play the long game, waiting in the soil for the temperatures to rise. Once it hits a certain threshold, they morph back into a more mobile, infectious state.”34 In a classic anthropomorphic rhetorical twist, the dormant bacteria emerge as uncanny actors with the power to shake the foundations of human life and society. They are not objects frozen by humans for technoscientific manipulation of life; instead, they are represented as invisible, potentially treacherous strangers within our seemingly familiar world.
At the same time, permafrost itself emerges as active and vibrant. While this is reflected in media stories of how ice that should stay frozen is melting at an alarming pace, it is particularly central to scientific accounts of pathogens, permafrost, and climate change. In an article published in 2011 and referenced in several of the 2016 news stories, medical researchers Boris Revich and Marina Podolnaya warn about the prospect of anthrax emerging at cattle burial sites in the Russian North.35 In a now ominous tone, the authors predict that resulting from “permafrost melting, the vectors of deadly infections of the 18th and 19th centuries may come back, especially near the cemeteries where the victims of these infections were buried.”36 Crucially, Revich and Podolnaya arrive at this view from an understanding of the melting patterns of permafrost as situated and heterogeneous:
As the permafrost temperatures in Yakutia increase, permafrost degradation becomes evident. For example, the depth of permafrost varies between 250 and 350 m in the center of this region (Yakutsk city). Under natural conditions, the depth of seasonal melting is 1.5–1.7 m for clay loams, 1.6–2.0 m for sand clays, and 2.0–2.5 m for sands. The temperature of surface layer of permafrost is predicted to increase by 1.5–2°C in West Siberia and Yakutia, and by 1.0–2.0°C in Chukotka and north regions of Far East.37
Here, permafrost is constantly shaped through local dynamics involving temperatures and the material qualities of the ground. Likewise, in an article published in 2020, environmental scientist Elisa Stella and colleagues examine permafrost’s cyclical nature of wakefulness and how it may affect dormant anthrax spores. Developing a mathematical model that accounts for seasonal fluctuations rather than simply annual changes, they argue that “the seasonal and inter-annual dynamics of the active layer, and of the top surface of permafrost, can critically control the viability of spores and, in turn, the risk of triggering anthrax outbreaks.”38
In these two examples from scientific literature, futures become pinned to the unpredictable, situated capacities of permafrost in specific material locations. The accounts thereby reflect Bravo’s and Cho’s theorization of permafrost as never stable and thus never quite manageable. The two examples also shift the focus of attention from the anthrax spores to the material entanglements of ice and soil as capable of shaping futures of health and illness. Affects such as anxiety and concern become attached to this unpredictability of melting ice and its potential ability to mold the future. At the same time, the ability of anthrax spores to come alive and cause outbreaks appear as dependent on these local peculiarities of vibrant permafrost. The perceived animacy of both anthrax spores and melting layers of permafrost are reinforced through their mutual entanglements.
Furthermore, the capacities of the anthrax spores and permafrost are made sense of through ideas of indigeneity in cultural discourses around the 2016 outbreak. As Hamilton notes, indigeneity and permafrost are historically entangled in cultural perceptions and are often interpreted through a popularized evolutionary framework of past-oriented (Indigenous) versus future-oriented (technoscientific) societies.39 In the anthrax case, the nomadic herders were perceived to have unintentionally played a role in the spread of the outbreak since their herding practices moved a large number of reindeer through small, anthrax-contaminated space.40 Furthermore, the culture of the herders was sometimes constructed as part of the problem. An article in Deutsche Welle, for instance, quotes a governor’s spokesperson saying that one of the families who were ill “ate reindeer meat raw and drank the blood,” adding that “the nomads do have this custom.”41 For the most part, though, indigeneity remained a relatively unprecise reference point whose affective power lay in the historically cemented popular association between indigeneity and permafrost rather than in any specific material detail.
In the media coverage of the anthrax outbreak, the association between anthrax, cold, and indigeneity operates through ideas of temporality. Anthrax was not only currently in the wrong place (outside the ice) but also originally in the wrong place (in the surface layers of permafrost). The burial practices of the past and unmarked graves were understood to have put anthrax in the wrong place. Anthrax was also in the wrong time: it belonged to the past, not the present nor the future.
At the same time, indigeneity has been commonly associated in popular discourse with the absence of modernity and as presumably unable to reach to the future.42 Such organization of temporality into (presumably) neatly separable temporal zones—past, present, and future—is the cornerstone of technoscientific ideas of progress. It assumes that the three temporal zones should be kept separate and that the past should not claim a hold over the future. Building on such spatiotemporal politics of cold, indigeneity, and pathogenicity, the nomadic herders became seen as symbolic of the anthrax-ridden past threatening the future. The reindeer carcass as a source of past anthrax spores played a key role in this representation, as the connection between reindeer and indigeneity has a firm place in the imperialist imagination.43 Familiar colonial images of racialized difference—reindeer herding, burial sites, endless ice—thus emerged in popular representations of the anthrax outbreak as the uncanny that challenges the inevitability of a future. This evocation of indigeneity, permafrost, and the past contributed to the affective intensity around the idea that past pathogens could threaten the future.
Past Pathogens and Evolutionary History
Popular discourses around the 2016 anthrax outbreak focused on the liveliness of the old anthrax spores and their capacity to threaten human health. However, the anthrax outbreak also engendered another type of knowledge: genetic sequencing of anthrax samples. Samples collected from the outbreak provided an entry point to placing the specific pathogen responsible for the outbreak in the context of the evolution of anthrax strains across time and space. This kind of genetic knowledge of pathogens has engendered considerable fascination in culture for its perceived high-tech approach and ability to reach back in time. In this, the sequencing of the anthrax samples from Siberia sits firmly within the larger project of aDNA research, which seeks to understand evolutionary processes through old DNA samples. The sequencing of the 2016 anthrax samples warrants attention, as it shows how aDNA research has expanded across bioscientific research, seeking to turn epidemics into sources of evolutionary knowledge. This case also provides a crucial contrast to the sequencing of the 1918 influenza virus, which—as we will see in the following sections—focused on the prevention of future epidemics. This shows that genetic knowledge of past pathogens occupies an ambivalent position as a means of knowing the past as well as managing the future.
