Predators, parasites, regulation and intervention in ecosystems

This post is inspired by this talk by Bret Weinstein. I support him on Patreon. The talk emphases a different aspect of the underlying problem. So if you read and like this, you won’t be wasting your time if you watch the video.

Ecosystems

The term “ecosystem” includes both ecological systems and economic systems. They behave in similar ways.

Evolution of predators and parasites

Within any ecosystem, parasites and predators will naturally evolve.

Unregulated growth

Without some form of regulation or invention, evolution will increase the number and kind of parasites and predators up to the limit that the system can support.

Evolution of defensive adaptations

Some hosts evolve adaptations that defend against parasites; some prey will evolve adaptations that defend them from predators. The defenses will only evolve after parasitism and predation starts, and will never be entirely successful.

Evolution of less damaging behavior

Parasites that initially kill their hosts will often evolve so that they don’t kill them, but keep them alive while extracting resources. A dead host is of less use to a parasite than a still-living one. In some cases, parasites will evolve to become mutualists and benefit their host even as they are benefitted.

Effect of interventions

Interventions and regulation to reduce the harm caused by parasites and predators will change the number and kind or predators and parasites in a system.

Response to interventions

Once intervention or regulation have taken place, new or different predators will evolve to take advantage of the changed landscape. Some existing parasites and predators will grow in numbers.

Need for evolving intervention

Because parasites and predators evolve in response to interventions, interventions must also continuously evolve to reduce the damage that parasites and predators have caused.

Opposition to intervention and regulation

You might be opposed to intervention in or regulation of an ecosystem if:

• You believe that there is something innately good about naturally evolved predation and parasitism and the natural order should not be disturbed
• You believe that interventions that are intended to reduce the damage caused by predators and parasites will make things worse
• You are a symbiote who benefits from predatory or parasitic behavior
• You are yourself a predator or parasite

Ecological intervention versus economic intervention

From a purely ecological view, human beings are predators and parasites. The human economy depends on human intervention in natural ecological systems.

This has been good for some human symbionts—dogs for example. Most kinds are more numerous and probably healthier and live more pleasureful lives because of humans. It’s been a mixed bag for some other creatures. There are more chickens, but the cage-raised ones might have worse lives than their free ancestors. It's good for news species that might develop from humans stirring the evolutionary pot. But it's been horrible by species decimated or extinguished by humans.

If you believe there is something innately good about naturally evolved predation and parasitism I think we have nothing to discuss.

Some people believe that all interventions in an economy—even those that that are intended to reduce the damage caused by predators and parasites—will make things worse.

It might be true, but by analogy with ecological interventions, it’s unlikely to be true. There are unintended consequences and interventions need to change with circumstances, but the facts are clear. We feed and supply the world through massive, continuing, and evolving interventions in ecological systems. If we did not intervene, ecological systems would produce about as much biomass as they do with intervention. It’s just that most of it will not be useful and much of what would otherwise be useful will be consumed by parasites.

Yes, the interventions have unintended and undesirable consequences. And as these problems show themselves people are working ways to change interventions to increase the benefits and to reduce the harms.

Without changing interventions, the parasites and predators that have adapted to the current environment will continue to evolve and grow to the carrying capacity of the environment.

(To be elaborated in an upcoming post.)

​