Everything that lives must live somewhere. The idea of habitat, at its core, is nothing more than the designation of a home for a particular form of life. In theory, everything that finds appropriate conditions for its own life requirements has found its habitat. If we are thinking along Darwinian and ecological lines, then chance provides variation in both beings and habitats, and chance yet again puts one in the path of the other.
This deceptively simple way of thinking about habitats hides how the issue of who belongs where is intensely policed by human practices, both ecological and political. In a strictly ecological sense, the distinction between migrants and natives makes no sense. Invasiveness, whether in human or biological terms, is simply the frustration of our expectations, and not a fact belonging to the world. Inasmuch as conditions of life are met, then one has found a habitat.
The political idea of invasiveness rests on the assumption that habitats in the sense used here are ‘matched’ to particular kinds of beings. Said differently, habitats are often seen as the appropriate home for a particular kind of being, as the place where that being should be. Though the difference between an ‘appropriate place’ and one that simply ‘works’ seems small, it is important and consequential. Seen from the point of view of natural selection, the notion of appropriateness is redundant: something lives where it finds conditions of life, and there is no necessity to the process. It is not as if habitat x, exhibiting conditions y, must on account of those conditions also be home to animal z. It might or might not, depending.
Let’s take an example to anchor this. Habitats are strictly defined by having certain conditions of life, so they need not look in any particular kind of way. A habitat always works for some kind of being. From this perspective, the human body is the habitat of countless microscopic life forms. The latest such being to enter the human-as-habitat is SARS-COV-2. And its rise and spread are an excellent illustration of the idea of habitat itself, and how it can be subverted for nefarious (and ultimately counterproductive) purposes.
Though the idea of each being belonging to one unique place is attractive for many reasons, it is not on that account a sound one. The norm in nature seems to be variation and redundancy, with different kinds of beings potentially living in different kinds of places, all of which are constantly changing. Indeed, the virus started off (and still exists) in colonies of bats and in the bodies of other animals. A chance event modified some of its offspring such that they became able to live in another habitat: humans. But it is not only the virus that has changed; humans have too, and in the process have redrawn the kinds of possibilities that they afford as hosts to new forms of life.
One decisive way in which humans have changed is by becoming incredibly numerous. A habitat is only good for someone as long as it can be reached, and if humans are few and far between the chance mutation of a virus in a colony of bats would, like most mutations everywhere, lead nowhere. The changed offspring would die, being ill suited to the habitat where it finds itself and not being able to find another, better one. But humans are everywhere, and so their availability as habitat is greatly increased. Not only are humans everywhere, but they are also packed closely together, which from the perspective of a virus is excellent news. Finally, humans handle lots of different animals and keep them close together, again creating habitats where none existed before. It is the coming together of all of these changes (and more) that make us appropriate habitats for a virus, though again – there is no necessity to the process; it is all a matter of probability.
The social distancing measures currently implemented in most of the world are a direct analogue to the habitat fragmentation that is driving the sixth great extinction of life forms on Earth. The problem with habitat fragmentation is that it interferes with the stochastic process of a being encountering conditions for its own life. It reduces the probability of such an encounter. If you are a small mammal (bats excluded as they’re the only ones that fly) that finds five highways between its current place of residence and the next suitable one, then any disturbance (that is, natural variability and change that matters to you) in your current home is probably going to be fatal. Your likelihood of reaching a new home is diminished by fragmentation. By keeping distance from each other, humans are now fragmenting themselves-as-habitat, such that the virus finds the equivalent of five highways between one human and the next. Long term, we’d better learn to put distance between us and potential new visitors by handling fewer wild animals, and changing how we handle the ones that we nonetheless must. That way we may eventually go back to huddling together, as befits social primates.
This ecological way of looking at the idea of habitat complicates the drive to assign fixed places to particular kinds of beings. And despite the fact that we are now enacting a grand performance of habitat fragmentation, the impulse to distinguish between what belongs and what doesn’t is as strong as ever. Trump calling the virus ‘foreign’ is a case in point (strictly speaking, a foreign virus implies it has come from outer space). So are the countless examples of racism and xenophobia that have accompanied the pandemic so far, each resting on the idea that the virus ‘belongs’ somewhere. Ecology, particularly in its public variants, is not making things easier by continuing to insist on the difference between native and invasive forms of life, lending credence to the idea that nature works by compartmentalization and nativist belonging. Unwittingly, this plays into nationalist discourse, which is nothing but another manifestation of the idea of a perfect match between habitats (nations) and beings (‘their’ people).
Though we are profoundly ignorant about nature, the view that best fits the facts is that nature works through variation and chance. To a very large degree what we choose to protect in nature is a reflection of our values, and not of the appropriateness of an eternal fit between a being and a place. Similarly, the idea of a divine separation between self-contained nations is an organisational fiction. The reality that it hides is one of perpetual variation and human multiplicity.
The ideas of variation, change and multiplicity point towards an important corollary, namely the notion of redundancy. In the natural world as much as in the human one, many forms of life repeat themselves with slight variations, and in that sense are redundant. Along a coastline, for example, there may be thousands of lagoons, each one slightly different, affording potential homes to endlessly variating animals. A tree will produce thousands of potential offspring, some of which may find new habitats, but not their brothers and sisters. The variety of human cultures nonetheless share many of the same fundamental concerns, expressed slightly differently. Viruses have lots of redundant human habitat.
The notion of redundancy is important, because it offers a way of expressing our concern for protecting precious aspects of the world without repeating nationalist and nativist tropes. Because nature continuously changes, it is never enough to have one of something. For example, if we protect the last habitat of a particular animal, we can be sure that eventually that habitat is going to change (despite our ‘protection’) and the only way that the animal will survive is by moving. But through fragmentation and the reduction of redundancy, we radically lower the probability of a successful move. The importance of maintaining redundancy becomes clear if we think of both habitats and beings in constant flux: the only way to increase the probability of temporary agreement between places and beings is by maintaining a high number of slightly different variables.
We can again see this principle at work in the current quarantine measures, albeit negatively: the more fragmentation, the harder for the virus to find habitats. Strictly speaking, reducing redundancy (human numbers in this case) would also have a strong effect, though that is not what humans want to do, for obvious and very well-founded reasons. But we can nonetheless see the importance of redundancy at work: the availability and massive variation in potential habitats makes it incredibly difficult to stop the virus from moving about.
Coming back to where I started: everything must live somewhere, and that somewhere counts as its habitat. If we are to stay true to the radically inclusive (and ecologically sound) core of this conception, then we must understand that both the idea of a living thing, and that of its habitat, designate open systems. Places are constantly changing, and the rate of change will only increase as the centuries progress, and beings themselves will also continue to change, as the latest SARS makes abundantly clear. While we are fragmenting ourselves to stop its spread to new habitats, we may be well served by contemplating the analogies between us as habitats and our destructive impact on the abodes of countless other beings. The virus does not belong to one imagined place any more than humans belong to Africa because they evolved there. Sooner or later we will manage to modify the virus’ habitat through medicine. We may even learn how to change our behaviors in ways that make it harder for future viruses to happen upon us. But the hardest task is to learn how to modify the sum total of habitats on Earth in ways that allows the richness born of chance and change to endure.