Unfettered Evolution: A Cornerstone of Wildness

"our appreciation for the crane grows with the slow unraveling of earthly history. His tribe, we now know, stems out of the remote Eocene...And so they live and have their being- these cranes - not in the constricted present, but in the wider reaches of evolutionary time"

Marshland Elegy, A Sand County Almanac, Aldo Leopold 1949

Wild nature, as we know it, is the product of billions of years of evolution, unfolding autonomously with no human oversight or management. In the Anthropocene, however, human activity has become a dominant force constraining future evolution. Despite these realities, we see little acknowledgement of the human obligation to protect the autonomy of evolutionary processes. We argue that the latter must be a critical priority in an ethic for conservation

“Wildness is a name we give to living nature, on planet Earth, at its most robust, unfettered, undiminished, dynamic, and diverse. … Wildness is biological”

David Quammen, What Is Wildness? The New York Review, May 16, 2023

Writing recently in The New York Review of Books (1) American science, nature and travel writer David Quammen delivered a primer on the conservation biology that we see informed rewilding as envisaged by its originators (2). In the context of defining wildness, Quammen identified four crucial ecosystem features: scale, connectivity, diversity, and processes. By processes, he meant the interactive dynamics of an ecosystem, such as “photosynthesis, herbivory, pollination, parasitism, competition, predation, seed dispersal, and decomposition”. He saw connectivity as the “linkages and dependencies that such processes build among living creatures and their physical environments”. He emphasised that scale is an ineliminable consideration because “connectivity and processes — and biological diversity too — all depend on the sheer size of the place where they exist”.

Quammen also laid out the tenets of island biogeography (3) before delivering its dire warnings for the present: as we “increasingly occupy the Earth’s surface and arrogate vast areas to our purposes” humans are fragmenting natural landscapes and thereby destroying their biological diversity. Quammen’s travels confirmed this reality, as he observed places of deforestation where local species were threatened with extinction. He averred that every loss from a great forest – from predators to pollinators to amphibians – diminished it, and that a large reduction in size or fragmentation with roads also diminished it. By progressively taking away scale, connectivity, diversity and dynamic processes, these acts of human appropriation would lead to the “heartbeat of the wild” growing weaker until it eventually stops, leaving a lifeless empty forest. But Quammen argued that it is not too late for humans to preserve those elements of wildness: the scale and connectivity of natural landscapes, the biological diversity within them, and the processes by which those living creatures and their environment interact.

A missing element

We can only agree, and we find Quammen’s viewpoint heartening in a contemporary context in which much academic and popular work purports to deny the very concept or continued existence of wildness (4). However, we believe that there is an element missing from Quammen’s discussion – unfettered evolution – that is even more fundamental to wildness. This missing element has two important facets: the autonomy of natural processes from human determination and the focus on evolutionary processes in particular. Quammen did not pinpoint autonomy as an essential quality of wildness, although his discussion often alluded to it, as when he described wildness as “unfettered” and “uncontrolled by humans”. Meanwhile, he did not seem to recognise evolutionary processes as something integral to wildness, despite the fact that many of his earlier books have dealt with evolution at length (5,6). On the contrary, he has at times written acceptingly of the role of humanity as an evolutionary force, such as in his review of the book Darwin Comes to Town by Dutch biologist Menno Schilthuizen (7). Conceding that humanity is now the dominant force governing the future of life on Earth, Schilthuizen argued that evolutionary processes are acting on non-human species living in urban environments at a faster pace than expected, a phenomenon that he dubbed human-induced rapid evolutionary change or HIREC (8). Schilthuizen saw this rapid change as a saving grace for non-human species eking out their living in an increasingly and inevitably human-dominated world. As an example, Quammen described Schiltuizen’s case study of the London Underground mosquito (Culex molestus), which became genetically distinct from its closest relative, the northern house mosquito (Culex pipiens), in a mere matter of decades, due to its adaptation to an anthropogenic urban habitat.

Following Schiltuizen, Quammen appeared to see merit in this accelerated evolution and diversification in response to anthropogenic pressures within human-controlled environments, suggesting that it might enable non-human species to resist their annihilation and allow us humans to sate (if only “slightly”) our appetite for nature’s beauty and wonder. To be sure, Quammen was not wholly optimistic about the human-induced rapid evolutionary change. He acknowledged that some species fare better than others in adapting to anthropogenic environments, that urbanisation acts an homogenising force on biodiversity, and that the formation of the new species like C. molestus would almost certainly fail to keep up with the rate of human-caused extinctions. However, we suggest that Quammen missed an even more basic problem with this concession to the role of humanity as an evolutionary force, and it appears discordant with his recent views on wildness. Why should non-human species be forced in the first place to adapt to our environments or perish? What of the wildness of evolution itself?

A lack of precision

Quammen is not alone in failing to bridge the connection between evolution and wildness. Originators of conservation biology and rewilding, such as Michael Soulé and Dave Foreman, recognized the importance of protecting the autonomy of nature and occasionally invoked evolution in this context. Even they, however, did not fully articulate the importance and implications of protecting autonomous evolutionary processes. In his well-known article from 1985 “What is Conservation Biology?” (9). Soulé included “evolution is good” as one of the four normative postulates of the discipline but said little to elucidate it. He recognised the ethical imperative “to provide for the continuation of evolutionary processes in as many undisturbed natural habitats as possible” but he did not elaborate what this means in practice, including the scale at which evolution must occur for it to be wild, despite the fact that he had previously written about the area of land needed for speciation (10).

Foreman also frequently alluded to evolution as a reason for rewilding. For example, the homepage of The Rewilding Institute, an organisation which he founded, prominently displays a quote from “Wild Things for Their Own Sake” one of Foreman’s personal “broadside” columns: “The most needed and holy work of conservation is to keep whole the building blocks of evolution. Such is the true work of conservation, the goal of those who cannot live without wild things” (11). In the essay, however, Foreman did not identify what those building blocks are, and he seemed to vacillate between talk of “building blocks” and the evolutionary processes that act upon them (12). He declared that we must “step back somewhere (many somewheres) so evolution is free to unfold for wild things in its own unhobbled, eerie way” but like Soulé provided no details about the scale required. He asserted that “evolution is wild” but this seems to either overgeneralise or trivialise the notion of wildness. After all, the human-induced evolution described by Schilthuizen is evolution, so is the evolution of pesticide resistance in insects or antibiotic resistance in bacteria – but ostensibly there is little “wild” about the environments in which this evolution occurs. 

Although Soulé and Foreman express an exemplary sentiment, their lack of precision ultimately leaves their work unhelpful on this topic. Most glaringly, perhaps, they have offered no resources to differentiate the unfettered evolution that rewilding must aim to protect from evolution that occurs in response to human-driven selection pressures, such as the urban evolution discussed by Schiltzhuizen and Quammen.

Respect for autonomous evolutionary processes

Our objective in forthcoming work is to remedy the striking omission of evolution from contemporary conversations on wilderness and rewilding, and to reassert and explicate the moral imperative to protect the autonomy of evolutionary processes. We will characterise the importance of evolutionary processes, why they should be unfettered by human influence, and what conditions need to be met for this to happen. We will describe why our position represents a unique and novel contribution to the literature on conservation and ecological ethics, detail the threats that embroil it, and offer paths forward. This far-reaching endeavour exceeds our present scope, but we offer this medium-form essay as a foretaste.

As a philosopher and a life scientist, we maintain that conservation is morally vacuous if it is not predicated upon respect for autonomous evolutionary processes. These processes antedated our own species by billions of years, and they are responsible for our existence and the existence of all other life on Earth. Although we will say more in future work to justify our normative position, we take it as self-evident that these processes are intrinsically good and worth preserving. At the same time, we believe that the Anthropocene (13) characterised by a human inability to be impartial to its own species (14) poses a grave threat to the freely unfolding productivity of the future evolution of life.

Evolution is the change in heritable traits of organisms within a population over successive generations (15). Stereotypically, this change occurs as a result of the passing on of successful gene combinations that permit organisms to survive and reproduce in the face of selective pressures imposed by their external environment. When conservation biologists speak about evolution, they commonly focus on genetic variability within and between populations of organisms (sometimes described as evolutionary potential), often with an interest in ensuring species survival or promoting future biodiversity (16). In contrast, our main interest comprises the evolutionary processes themselves – processes such as natural selection and gene flow that determine the evolutionary trajectories of populations. We believe that conservationists have a mandate to ensure that, to the extent possible, the selective pressures that drive evolution are allowed to be chosen by the free-flowing processes of wild nature instead of intentional human judgement.

Human domination of evolutionary processes

At present, human activity has become a dominant force shaping the evolutionary trajectory of life on Earth, which threatens to lead to the erosion of the very existence of wild species (17). The anthropogenic transformation of the biosphere will irrevocably change non-human species to the point that the autonomy of their free living is severely constrained, if not lost entirely (18). Crucially, however, we believe that this present de facto domination by our species does not justify concession to ongoing human management of nature, or abandonment of the aspiration to protect wilderness. On the contrary, humanity can – and must – choose to reverse our course of domination and return significant portions of the planet, at the right scale, to a self-governance by unfettered evolutionary processes. This entails not only preserving areas of land and sea as uninhibited as possible by human-derived selection pressure, but also permitting the continuation of all natural selection pressures, including predation.

We see very little in the literature that so much as recognises this real threat of human domination of evolutionary processes. On the contrary, we have observed the rewilding movement digress even farther from Soulé and Foreman’s gestures toward the need to safeguard evolution and their emphasis on the autonomy of nature. As advocates for rewilding as envisaged by its originators (2) we have been dismayed at the constant stretching and redrawing of the boundaries of the concept in Europe and elsewhere, as practitioners and stakeholders attempt to dictate what rewilding means through ongoing compromises that have resulted in its domestication (19,20).

Proposals for the assimilation of farming to rewilding (21) urban rewilding (22) and other attempts to introduce so-called rewilding into anthropized landscapes capitulate to human influence on selection and gene flow, and common prescriptions for the use of domesticated species in rewilding projects overtly introduces artificial selection into the practice (23). Meanwhile, the new domesticated rewilding often forsakes the restoration of natural selective pressures, mostly notably by downplaying the importance of large carnivores to ecological processes, as do other interests (24-27). The moral mandate to ensure the perpetuation of unfettered evolutionary processes removes any legitimacy of all such compromises.

Predation has been an important driver of natural selection since at least the Cambrian (28,29). Despite this evolutionary reality, we have seen this fundamental ecological process under attack from multiple quarters, including so-called "animals rights" theories in moral philosophy. For example, recent work by philosopher Martha Nussbaum has suggested that we ought to curb predation in nature, or avoid reintroducing large carnivores, for the sake of preventing the pain and suffering of sentient animals – “intelligently respectful paternalism is vastly superior to neglect” (30). This sentiment is far more extreme than compassionate conservation (31) because it implies that the wild needs stewardship, human intervention to prevent predation, and that wilderness can be improved upon. Nussbaum herself has skirted this issue by claiming that none of the Earth can truly be considered wild, but this is beside the present point; her position seems to entail that if wilderness does exist, we would need to destroy it, under the guise of improving the wellbeing of the individual animals therein - “When humans do not intervene, Nature does not attain a stable or balanced condition, nor does it attain the condition that is best for other creatures or for the environment” (32). The logical endpoint is the herbivorizing of carnivores, which is in fact the aim of the research of a newly formed advocacy organisation whose strapline is “Leading Evolution Compassionately” (33). If this, unlikely to us, proposition was to have any realisation, then it would be a gross attack on self-regulating evolution by removing a biotic interaction that is one of the key processes that shapes its outcome. In essence it is an acquiescence to the purported “end of nature" in Bill McKibben’s prophetic book from 1989 that he previewed in The New Yorker (34) so that there is instead a human governance of the evolutionary futures of life on Earth.

We find it dispiriting that contemporary moral theories have been proffered to justify this sort of deliberating undermining of natural evolutionary processes, while none of note have been put forth to argue in favour of the moral importance of respect for the autonomy of these processes.

Transforming ourselves out of the lock that the Anthropocene has on us

In forthcoming work, we will address an array of other adversaries, from speciesism to social constructivism about nature. We will counter the objection that humans are merely a part of nature – another “ecosystem engineer” like so many other species (8) – and that it is thus only “natural” that humans impinge upon their environment and, in doing so, influence the flow of evolution. In addition to challenging intellectual adversaries to unfettered evolution, we will examine the pressing threats of human overproduction, overconsumption and overpopulation, which directly and increasingly impinge on our ability to ensure the perpetuation of wild nature and its self-directed evolutionary processes (35-37). It is our species’ moral imperative to acknowledge these realities, to recognise the power and ownership structures that facilitate them, and to transform ourselves out of the lock that the Anthropocene has on us.

In the meantime, there must be a revitalised strategy for conservation and rewilding based on strict non-intervention, at a scale large enough to permit significant global populations of non-human species to remain subject to natural evolutionary processes. Existing protected area systems fail to designate sufficiently large and connected strictly protected areas to allow speciation to occur naturally, especially for large mammals (10) and there is no widespread commitment to strict non-intervention (38,39). Correspondingly we believe that ecological restoration must be predicated upon respect for evolution’s own past choices, not dictated by human-desired outcomes for biodiversity or ecosystem services. Our hope is that by focusing upon evolution, and in a manner removed from human interpretation and influence, we can foreshorten the endless and revolving discussion and procrastination so that a revitalised strategy for conservation can be promptly realised.

Kate McFarland and Mark Fisher 16 June 2023

This article is cross-posted on Kate McFarland's website at Ohio State University

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mcfarland.309@osu.edu https://u.osu.edu/mcfarland.309/  mark.fisher@self-willed-land.org.uk http://www.self-willed-land.org.uk/