Documentaries about evolution and the 5 mass extinction events that have occurred on this planet never mention fungi, even though they could be considered the stars of the show, the computer generated special effects of things exploding and living thing dying sell a lot better than the micro wonders going on in the soils of the earth. Plants that formed symbiotic relationships with fungi were better able to survive the blanket of darkness caused by dust blocking out the sun. These fungi basically gave nutrients to plants helping them survive the difficult transitions.
Fungi were the first lifeforms on land, over 1 billion years ago. Although they now feed off organisms that were once alive they didn’t start out that way. When they first came to land they evolved to produce enzymes to break down the different types of rock to release nutrients and energy they needed to survive. This was the slow process of making the first soils that simple plants would need to get a foothold on the land. Once plants came to the land fungi had a new food source that because of the enzymes they evolved to break down rock could now be used to break down an easier food source.
Now things get interesting. The more plant material that died the more fungi diversified, more soil was created and the more plants could venture onto the land, not only that but plant-fungi relationships started to develop. Fungi retained the moisture in the soil, also making the soil spongy holding even more moisture through a web of mycelium and shared that resource with plants which made it easier for plants that paired up with fungi to colonise yet more land. This process created relationships that over time meant most plants could not exist in soils devoid of fungi. Orchids are a good example. They paired with fungi and depend on them so much that they cannot exist at all without their fungal partner, their seeds are so fine they need the fungi to produce food for them while germinating. It’s also interesting that Orchids were one of the first plants to produce flowers which is why the orchid family is so large, they have had that much more time to evolve into more species.
Speculation that fungi formed small ecological communities allowing small animals and plants to survive. It's not hard to imagine fungi feeding off dead plant and animal materials providing homes for surviving plants and insects that fed the few larger animals, possibly in small pockets or oasis.
White Rot Fungi Slowed Coal Formation
There is now good evidence that the evolution of fungi somehow cotributed to the extinction of Lepidodendron and other Lycopsids. All that is left of this line of plants are a few inconspicuous ground-covers. These tree and shrubs if they can be called that contributed to most of the coal in existence today. Whether white decay fungi killed them directly or these trees failed to form relationships with fungi to help them through the extinction events is still unknown.
Mycoremediation is a process where fungi are used to take pollutants out of the environment. Many species of mushrooms are capable of taking different pollutants/heavy metals, radioactive particles out of the ecosystem and concentrate them in their fruiting bodies making them easier to dispose of. Mushroom mycelium can produce enzymes so strong they will break the carbon/hydrogen bonds as are found in fossil fuel. P. pulmonarius is especially effective at turning hydrocarbons into sugars
There is a direct link between how polluted the environment is as to how toxic pathogens are. If the water is dirty bacteria need to produce more toxins to protect themselves, in clean water they are no where near as toxic.
Bio-Fuels from fungi
Bio-fuels can be created from the sugars released by the breakdown of wood and plant material by white decay fungi. The carbon released by these fungi are going to end up back in the environment anyway so you’re not releasing any added carbon back into the environment like you are with coal, gas or oil. The beauty of this technique is that it requires no harmful chemicals to break down the lignin and virtually no energy like heat is needed, all fungi require is oxygen, everything else the white decay fungi need they can obtain from the organic material they are breaking down so require no fertilizer. There will be enough carbon left in the resulting compost along with all the other nutrients released by the enzymes the mushroom mycelium has released for the compost to be used for growing crops and for introducing the compost into areas where nutrients have been depleted in the soil from over use.
There are also fungi that make fuel directly avoiding the whole process of obtaining and refining crude oil.
Micorrihizal Fungi are usually those fungi that have a definite symbiotic relationship with plants, and are also very expensive. In this group are Truffles, Saffron Milk caps, Porcini, Chanterelle and Bolete, also the deadly Amanita. It was found that these fungi do better in soils low in nutrients, the reason was that the trees had to need the fungi to provide the right relationship for the fungi to then produce fruiting bodies. The trees gain a fair amount of nutrients from the fungi and the fungi are supplied sugars from the trees. In healthy soils the trees don't rely on the fungi as much and so the crops are smaller or almost non existent.
Micorrihizal Fungi can also help with drought tolerance in plants allowing some trees to grow outside their normal ranges.
I can not emphasize enough the danger of consuming UN identified mushrooms. If in doubt throw it away. If you are curious about mushrooms and fail to identify them correctly it's on you. Watch this video to get the message to sink in. https://www.youtube.com/watch?v=SwnYfFQSyZM
The video is explaining the symptoms of the deadly Amanita mushroom or death cap but similar symptoms will occur with most poisonings.
Fungi are so closely related to animals that recently a new Kingdom was suggested joining fungi and Animalia together called Opisthokonta. On the evolutionary clock we and fungi branched off most recently in the very last hour. We have many similarities with fungi. We must consume other lifeforms to get the energy and nutrients we need. Animals have internal stomachs; fungi have external stomachs. We both need oxygen to breath. We are both heterotrophic which means we inherit characteristics from 2 parents. We have senses that can detect vibration, the beginning of sensation and touch. We both crate chitin to strengthen cells. We have the same diseases like bacteria and viruses which is why most antibiotics and anti-viral chemicals fungi produce work just as well for us without causing us harm.