The Invasive Dynamic

The invasive dynamic helps explain the global spread and dominance of supermarkets and megachurches

Photo by CHUTTERSNAP on Unsplash

One profound and prevalent feature of our increasingly globalised world is the seemingly unstoppable onward march and spread of non-native species. It is surprising just how many species around us in our “natural habitats” are in fact non-native. Even some of our most loved and cherished species in the UK, such as horse chestnut trees and rabbits, are not “native to these parts”.

Not all non-natives have an adverse impact on their new homes, some even help increase native biodiversity¹, but there is a subset of non-native species whose impact on our environment is almost always negative: the aptly named “invasive species”. These animals and plants have the ability to take over and dominate natural habitats, outcompete or kill native species, and damage even urban environments.

Our natural ecosystems are finely tuned, complex, and intricate webs of different species and their interactions between each other and their environment. Like with any finely-tuned complex system, a small change can have unpredictable impacts that reverberate throughout the entire ecosystem. Thankfully, the complexity of ecosystems and their property of redundancy² means they are usually resilient to small changes and shocks and are able to bounce back, restoring the natural order. However, a considerable shock or change can knock the system permanently off balance, leading to a cascade of changes and degradation. Invasive species are a prime example of a considerable shock, with their arrival causing extensive and long-lasting changes to the structure and function of ecosystems and their communities.

Why is an invasive species so powerful?

Fundamentally it is because invasive species are novel. Thus the ecosystem is unprepared for their arrival. They are outsiders to the ecological relationships (e.g. predation, symbiosis, and niche partitioning) that have formed over extensive periods of time, keeping the ecosystem in balance, and functioning optimally. However, novelty, though essential, is not in itself enough to cause severe ecological damage. To be an invasive species, a non-native must be able to powerfully exploit their new habitat and become agents of significant change. They do this by subverting or breaking down natural ecological relationships and outcompeting their newly found rivals. Some invasive species are gifted with traits that allow them to rapidly expand in their new habitats, whether by being able to more efficiently utilise resources, or having an adaptation which fits well with their new home thus giving them the competitive edge. Others bring along with them a new disease that the ecosystem has not been exposed to before and has no immunity against, while for other invasives, there are no predators or parasites to keep their numbers in check.

Once they have gained control, invasive species can re-engineer habitats making them more suitable for themselves. They do this by “changing the rules of the system” enhancing further their competitive edge, and/or making the conditions of the ecosystem unsuitable for other species. Eventually, the invasive species achieve what they set out to accomplish — dominion. Instead of native diverse ecosystems, an invasive-dominated ecosystem is monocultural, often devoid of beauty and certainly devoid of abundance.

I believe the concept of invasiveness has relevance for many areas of our human societies. We see the same dynamics in the spread of monopoly businesses; in new and revolutionary political ideas; and in new disruptive technologies. These all exhibit what I call the Invasive Dynamic: ‘when something or someone is a novel disruptive force in a social-economic system, initiating changes or taking advantage of system attributes to give them the competitive edge to become dominant or pervasive, resulting in negative consequences for Societal Good.’

The rise of the supermarket

One area of modern society where the invasive dynamic can be readily perceived is the spread of the supermarket. Pre-1950, diverse local food stores, often owned by local families, were the prevailing food proprietors in most areas of the UK³. They provided much loved and often personal service along with stocking local and traditional foods unique to their localities. No individual shop sold all the products a family needed for the week, the greengrocers, the butchers, and the bakers would all have to be visited. Diversity in the local food system was high and local economies were strengthened, providing jobs for a great number of the community and support for local farmers. And as I have outlined here, the immensely personal nature of the businesses aided social cohesion and helped to create a beautiful society. However, the diversity of the local food system was not necessarily conducive to ease and convenience (having to visit numerous stores took considerable time) and prices remained relatively high when compared to today.