I was introduced yesterday to the FIMS hypothesis by PBS Eons.
The Fungal-Infection-Mammalian-Selection (hey that ryhmes!) hypothesis asks the question of why reptiles didn't bounce back as much as mammals did after the asteroid K/Pg extinction event.
After all, they need less energy than mammals as cold-blooded creatures, and they produce way way more offspring than mammals.
One theory is fungi: there was an explosion in fungal activity after the asteroid due to the now dark and dingy hellhole the Earth became, and a ton of fungal spores were floating around at the time, as seen in geological record.
Apparently fungal infections are not that deadly to mammals (it just irritates us), but were disastrous for reptiles. Plus us mammals had a new food source in the absence of plants and meat.
There's no conclusive proof, still, it's an interesting theory as to why the dinosaurs didn't bounce back and why us mammals took over.
You know, I was convinced that my chickens would eat any leftovers from the fridge that were about to go bad, but the one thing that they wouldn't touch was mushrooms. I didn't realize that the reason for that went all the way back to the extinction event that killed the dinosaurs.
For what it's worth, they and other livestock love mycelium from culinary species like Pleurotus ostreatus. The substrate is healthy myceliated straw/grain with the complex carbs predigested by the fungi and it has immune system benefits for them: https://openagriculturejournal.com/contents/volumes/V17/e187433152305260/e187433152305260.pdf
My ideal homestead revolves around multi-tiered green recycling using them. The fungi break down the garden waste that the chickens won't eat, the unproductive mushroom colonies go to the chickens and pigeon towers, the manure and eggshells go into the vermicomposter and garden. Those mushroom colonies are a major cash crop with a myriad of health benefits depending on what you're growing.