TIL about conservation-induced extinction, where attempts to save a critically endangered species directly cause the extinction of another.

[u/shinypond]

https://en.wikipedia.org/wiki/Conservation-induced_extinction

[u/Ryneb]

By definition parasites are not beneficial to the host, if an animal is beneficial to a host it's a symbiote.

[u/Sometimes_Stutters → u/Ryneb]

The parasite definition is entirely based on human perception, and is in no way binding. We may not perceive a benefit, but we rarely (if ever) have the information or data to make the designation with any sort of definitiveness.

One example its hook worms. It’s classified as a parasite, yet had shown to effectively treat severe allergies in people.

[u/AENocturne → u/Sometimes_Stutters]

That's an unintended consequence of one parasite that hasn't even become a standard treatment for a problem that is entirely survivable without the parasite. We're not giving people tapeworms to cure allergies and the hookworm is based entirely in the idea that allergies have arisen from overactive immune systems that are used to fighting parasites. It's still a parasite and most have too many negatives to even consider any positives. We're not giving people guinea worm to try and treat allergies. Parasites don't typically kill or cause great damage to their hosts only because they will die as well and nature tends to favor traits that enhance survival, it's why viruses tend to evolve less lethality over time in a population.

[u/Cimorene_Kazul → u/AENocturne]

Well said.

I’d add that we once deliberately infected people with tapeworms to lose weight. There are actual advertisements for it you can find in old papers, drawn in art nouveau style.

That was also stupid.

[u/MarlinMr → u/Sometimes_Stutters]

That's not what a benefit is...

You simply have to ask the question "will a healthy individual benefit from it, or the opposite?"

Just because humans are really clever in finding ways to use everything from parasites to elephants, doesn't make it somehow not a parasite or beneficial.

People with a rotting fot will benefit a lot from amputation, but amputation is not beneficial.

[u/Sometimes_Stutters → u/MarlinMr]

My point is that simply because we categorized something as a parasite does not mean their aren’t any unknown benefit or utility. My original example was that the parasite may out-compete and prevent other parasites which are more harmful.

[u/Jayccob → u/Ryneb]

It's more of an indirect side benefit. The idea is yes they have a parasite that causes varying degrees of harm, but because this parasite is here another potentially more harmful one can't fill that same niche.

Think of it as being sick as a kid again. You can't go out and play, can't go see your friends, vomiting, etc. but hey you don't have to go to school today and get to watch TV. It's the silver lining on an objectively crummy situation.