Honestly, that's what's so frustrating about the "life goes on" dismissive argument some folks use to dismiss calls for climate action.

Yes, it's true. Not every species goes on, though, and those that do don't necessarily enjoy the process.

I'm not sure if you're joking, but I honestly do think that adaptations of this sort, and zoonotic diseases in general (like Lyme disease or COVID) are the weapons of ecosystems that want humans to stay away.

What do you mean by this? Like COVID is the result of an evolutionary process that selected a disease that kept humans away?

That doesn’t make sense, in fact, it’s way more likely for diseases to become less deadly over time. Killing humans or making them very weak is bad for its survival.

I'm making a few assumptions in order to lump COVID in here, I'm just not familiar enough with it's dynamics in bats to argue about it specifically. I do think the principle is the same though.

In a recent biology class we spent a few lectures talking about Lyme disease, so I am familiar with that one. Here's the idea:

Ticks aren't born with Lyme disease, they get it from an animal and then transfer it to another animal. Not all animals are competent hosts for Borrelia Burgdorferi (the bacteria that causes Lyme disease). If a tick bites an infected deer and then bites you, you're unlikely to be infected (although if you do, then both you and the deer will suffer for it).

Mice however, are competent hosts for B. Bergdorferi. Also, neither ticks nor mice experience any negative affects from being infected (I'm told that bats are this way with COVID).

So look at it from the perspective of the pathogen. You have a limited complexity budget. You can't hack every single immune system, you have to be choosy. (Bacteria get their diversity from horizonal gene transfer, so data about which adaptations are effective in the current environment is sort of gossiped around.)

Meanwhile, look at it from the perspective of all of the potential host immune systems. Nobody wants to be infected, but certain organisms may be able tolerate infection better then others.

So there's this tension where B. Bergdorferi is looking to specialize re: hosts and each host genome has to "decide" how to handle it.

For reasons unknown, the B. Bergdorferi genome chose to specialize with the mouse. The effect of this "choice" is that it is more concentrated in areas where mice don't have many predators, and less common in places where they are well-hunted.

It's known that the impact of human settlement is uneven: It bothers the raptors more than it bothers the mice. So coincidentally, we have this situation where Lyme disease causing bacteria is concentrating in tick guts specifically where humans settle and upset the preditor/prey balances around the mouse.

And recall that this outcome, where it's the mouse and not some other tick-victim that ends up being the competent host, it's the result of tension between the genomes of all the things that ticks bite.

So I ask: is it mere coincidence that it ended up being the mouse that B. Bergdorferi specialized against? Or have the forest dweller genomes "collaborated" to achieve this outcome.

I don't think it's that wild to assume collaboration. Sure, they didn't sit down and discuss it, but given that human-driven habitat loss is a significant driver of extinction, I think there would be a selective pressure towards collaborative outcomes that keep humans out of the forest and away from ones that make the forest more inviting to humans. Perhaps there were cases where the B. Bergdorferi ancestor specialized in other ways, but we don't know about them because instead of forests there are parking lots in those places.

In this way, I expect that zoonotic diseases are a sort of immune system against habitat loss

Hypotheses are no good if not falsifiable, so here's the prediction: novel zoonotic diseases will spring up in places where human-caused habitat loss proceeds in novel ways. If we change how we live such that we don't create a safe haven for mice but do create one for some other creature, then the ecosystems that we're destroying will collaborate in new ways to cause that creature to be a threat to us.

I'm not sure where to look in history for examples of this, otherwise I'd be writing a paper about it, but I hope you can see how it would plausibly be applied to COVID as well.

Okay so if I am understanding you correctly, your theory is this:

“Diseases from animals have evolutionary pressure to hurt humans because hurting humans is better for the survival of its preferred host.”

That does make sense to me, but I think it doesn’t track with how slow evolution works.

According to Yale, Lyme disease has likely been around in North America since 60,000 years ago: https://medicine.yale.edu/news-article/ancient-history-of-ly...

Natives were not very destructive to forests and I don’t think very destructive to mice.

Mass deforestation to the level of evolutionary pressure would have come when Europeans first settled. Meaning Lyme disease would have had to specialize after that, which I would assume is unlikely.

Maybe the diseases do specialize to harm humans, but it feels like the period where diseases can effectively stop humans and humans were doing mass deforestation is too short. Lyme disease is problematic, but it hasn’t stopped anyone from chopping down trees.

You could argue it has the opposite effect. We drain swamps because of malaria, destroying its habitat.

I was perhaps too zoomed in on the details of how interspecies evolutionary pressure would work. Sorry for the wall of text.

My theory is that some ecosystems have a niche for pathogens that remain at low concentrations in healthy circumstances, but that become amplified in cases where the ecosystem is taking damage.

The article you linked describes such an amplification:

> “The Lyme disease bacterium has long been endemic,” she said. “But the deforestation and subsequent suburbanization of much of New England and the Midwest created conditions for deer ticks—and the Lyme disease bacterium—to thrive.”...

> Ticks expanded into suburbanized landscapes—full of animals like white-footed mice and robins, excellent hosts for B. burgdorferi

It may not have been humans that posed the initial differential threat to everything-but-the-mice-and-robins. But something did, and that created the pressure to arm mice and robins with invader-discouraging pathogens, and that pressure made B Burgdorferi what it is today.

The increased pathogen concentration is an immune response. The stimulus is a reduction of predators (which are known to be more sensitive to habitat disruption) and the response is that the prey, left unchecked, amplify the pathogen and infect the invaders.

Weapons are intentional, and ecosystems don’t do “intentional” on their own; you could even call this lack of agency a defining quality of a natural ecosystem.

Genomes also don't do intention on their own, and yet venomous pointy things like spines and teeth and claws evolved. Do you think we're unjustified in calling them weapons?

When they’re in use as weapons by the thing that possesses spines, teeth and claws: yes. I use my teeth to chew my food, my cats use their claws to manipulate their environment and grab things, but if we turned them against you, then they’re also weapons. The venomous pointy things et al. are emergent properties of a multi-stream evolutionary chain that makes every extant species on the planet pretty much a badass, even pandas, and we’re all pretty dependent on whatever properties we currently have allowing us to continue to exist, else it’ll be down to pure luck of the mutate.

The ecosystems all those species thrive or at least survive in though? Those don’t do intention. Ecosystems are a collection of species and are about as harmonious as a poison jar over time, but the jar itself has no intentions, it’s just a jar.

We can nit-pick over the word weapon if you like, but whatever you want to call it, it really smells like the kind of thing that repeats like a fractal.

Cells use organelles to maintain homeostasis in the presence of threatening stimuli, and organs use cells, and organisms use organs... I see no reason to assume that ecosystems don't use organisms in the same way.

Yes, because these are emergent phenomenon. Ecosystems are by definition too complex to have anything cognizable as intent. New diseases are an emergent phenomenon because the new species of bacteria or viruses we either find or which evolve around us interact with us in new ways, and those are all emergent phenomenon.

If something is emergent, that is by definition not with intent. My intent and your intent and everybody else’s intent creates both strong and weak interactions which percolate through society, recognizable through other phenomena which we measure such as economy, births, deaths, elections or whatever sum up into a society which is recognizable as a describable body but which is emergent and without an intent of its own but rather multiple sometimes overlapping and sometimes clashing intents. Ecosystems are like that: full of creatures with intentions of their own, but without any sort of intent. It cannot use anything without a body (a tree, a bee, a fox, a bacterial culture, a virus) taking action, therefore it cannot weaponize anything.

Or put another way, you can go into the Jungle, and you might die, and some lazy mofo might say you died from the Jungle but what actually killed you would be a crocodile, a jaguar, some kind of infection from an identifiable bacteria or virus even if left unidentified, maybe your inability to metabolize due to protein starvation, or something else, but the Jungle itself will not be the thing that killed you.

People talk about "then invisible hand of the market" or "fate" or a great many other things as if they have agency. They also talk about themselves as if they have agency. But so far as I know there's nothing rigorous behind any of it, it's just stories that we tell about phenomena.

Which circumstances are emergent and which are consequences of the intent of some character or another is more of a stylistic choice on the part of the storyteller. And if there's no story being told, then everything might as well be emergent.

I can see that we differ in how we prefer to style discussions about ecosystems, and that's fine, but so far as I'm aware there's no evidence to make one of us right and the other wrong. We're well away from science and squarely in the unknowable here.

Or put another way, the mofo that wasn't specific about which facet of the Jungle killed me is not as lazy as the one that that failed read the room and adjust their usage to fit the story that was being told at the time.

First:

> Ecosystems are a collection of species and are about as harmonious as a poison jar over time, but the jar itself has no intentions, it’s just a jar.

Then:

> Ecosystems are by definition too complex to have anything cognizable as intent.

Which is it, are they too complex, or too simple?

I do think that "cognizable" is the right word though. It's not about complexity. Whether a phenomenon is emergent, or the result of intention, depends on how we're thinking about it. It's a rhetorical choice, stylistic, not a matter of fact. It has to do with how you're telling the story, with whether its a character or the environment that does the thing.

I can see that you have different preferences over how to style conversations about ecosystems, and that's fine, but do you think there will ever be evidence that sorts this out for us, or are we just fighting over words?

Fighting is a strong word. I wouldn’t say we are, but perhaps you want to fight about that? :)

> Which is it, are they too complex, or too simple?

Poison jars are not simple. If you’re unfamiliar with the concept, the basic idea is that you place a collection of venomous insects and animals within a jar together and they essentially kill each other; the theory being that the poison from all of them would be concentrated in the survivor which would then be fed upon by larvae of which the last surviving larvae would hold the more complex poison.

It’s an imperfect analogy, but to break it down: the jar in this analogy is Earth, and everything living on it is competitive in a way which results in a complex but violent system of interactions. The jar could also be a given ecosystem smaller than Earth. The poison is is the result of the struggle. It’s an old Chinese idea, if you want to look it up look up “Gu” with “poison jar” in your search terms. The actual use of the poisons aren’t any more interesting to me than rhino horns or Astrology but the form of production itself is interesting, but I digress.

This complex system of interactions is basically life as we know it, and while it is not always clear to us how an interaction causes a significant impact on us either specifically or generally, we do know that occasionally something seemingly unrelated to us does. Earth is a closed system full of biomass quite literally the world over.

> Whether a phenomenon is emergent, or the result of intention, depends on how we're thinking about it. It's a rhetorical choice, stylistic, not a matter of fact. It has to do with how you're telling the story, with whether its a character or the environment that does the thing.

These are mutually exclusive. Emergent phenomenon can be caused by the complex interactions of intentional acts, but the phenomenon themselves have no intent. It’s not merely a rhetorical choice, because ecosystems tell no stories, we can only ascribe stories to them. Or put another way, I’m anti-ing your entire conception that an ecosystem of any sort at all would take any kind of action against an individual species within it because that would require an ecosystem to have some form of intent. Even if you didn’t mean it literally, it is a turn of phrase which encourages in others to see something in the natural world that simply isn’t there.

That you can get bit by a tick that causes a beef allergy is interesting and the tick, the cause of the allergy and what exactly happens that is beneficial to the tick are interesting questions; but the only intent here is the tick taking a bite out of its food because it was hungry and it does what ticks do. Unfortunately this also causes a beef allergy in some people but that is neither here nor there from the perspective of the tick or the environment from which it came.

I did a search but didn't look closely enough, so I had taken the jar comment to mean "mere container". Thanks for explaining.

I'm not sure I like the metaphor because everything in the jar is doomed, there are no opportunities for the alternatives to arise that the jar must choose between and no circumstances where that choice then affects the survival of the jar.

Because I recognize that many are uncomfortable with the idea that things without brains might make choices, I was trying to speak in a way that let "choice" be a stand in for a scenario where selective pressures on some group of species cause an adaptation in some other species which benefits the survival of the initial group. "Intent" being added by the storyteller (me) to help with the explanation, but without importing any claims about cognition.

I was avoiding taking a stance about whether the ecosystem makes a choice in the more traditional sense, with cognition in the mix, because I don't have any evidence of that, and I probably never will.

But you're taking a stronger position. You're saying that it absolutely does not have the capacity for intention. That strikes me as unknowable, how can you be sure? Presumably this:

> because ecosystems tell no stories, we can only ascribe stories to them

My dog tells no stores, but I think it's reasonable to talk about her intentions. When I'm playing a game against an adversarial AI and it attacks or defends, it's reasonable to talk about its intentions.

We are the storytellers, we get to decide which part of our stories are the setting (emergent phenomena) and which parts are the characters (intentional action).

They're mutually exclusive for any given story. But you can always tell a different story where the white blood cell is no longer an emergent phenomenon of the immune system but is instead a defender of the realm. As long as the stories are helping you make falsifiable predictions at the end of the day you're still going science.

> Even if you didn’t mean it literally, it is a turn of phrase which encourages in others to see something in the natural world that simply isn’t there.

As mentioned, I was avoiding taking a stance about it because panpsychism is out of scope here, but I did mean it literally.

Science can't even establish an objective understanding of human intention. Some would say that our choices are emergent phenomena and the feeling of having made them intentionally is a delusion. I'm not one of those people, but that's where stasis among cognitive neuroscientists is.

We're nowhere near where we'd need to be to assert that a complex system does not have whatever it is that we do, we can't even be sure that we have it.

That's why I want to defend my habit of treating things like ecosystems as if they have intentions, we can't know objectively either way, so it's fair game for creative explanation. It's also more fun.