How Fungi probably Shaped Life on Earth

Fungi are amazing organisms that can do many things, from helping plants adapt to land, to curing diseases in humans. They are neither plants nor animals, but a unique kingdom of life that often goes unnoticed.

Through a billion years of evolution, they have learned how to survive in any environment, and have started to do remarkable, almost magic-like things. Fungi have played a crucial role in the history of life on Earth and yet don’t get any credit; Without them, there would be no land, plants, animals, and everything else you can think of.

Fungi were among the first complex life forms to colonize land; breaking down rocks for mineral nutrients, and gradually creating soil. In the Late Ordovician era, they partnered with liverworts, the first plants to emerge from the water. Liverworts are small nonvascular plants that look like flat leaves with rounded lobes. They are part of the division Marchantiophyta, which has more than 9,000 species worldwide. Liverworts have a relatively simple structure, with a plant body called a thallus that is not differentiated into leaves, stem, and root. Liverworts are important for the ecosystem, as they provide food for animals, facilitate the decay of logs, and aid in the disintegration of rocks (so bad for your property). Fungi helped plants evolve from being these small marginal things on the water’s edge to large forests and whole ecosystems. The fungi supplied vital minerals for land plants, allowing them to grow and turn the planet green — altering the atmosphere.

Three hundred and sixty million years ago; in the Devonian era, On land, there were no trees yet, but the first vascular plants with leaves and roots began to appear. The only animals on land were invertebrates, such as arthropods and mollusks. Arthropods are animals with jointed legs and exoskeletons, such as insects, spiders, scorpions, and millipedes. Mollusks are animals with soft bodies and shells, such as snails and slugs. These invertebrates evolved from aquatic ancestors that gradually adapted to terrestrial environments. They were able to breathe air, move on land, and avoid drying out. They also became important sources of food for the first land vertebrates that emerged later in the Devonian.

But huge fungi dominated the landscape. Prototaxites were giant fungi that could reach up to eight metres in height and one metre in diameter, making them the largest land organisms of their time. They had a columnar structure with concentric growth rings and a complex network of tubes and filaments. Prototaxites evolved from aquatic fungi that colonized land in the Late Silurian era, about 420 million years ago. They formed symbiotic relationships with the first land plants, such as liverworts, and helped create soil by breaking down rocks and organic matter. Prototaxites dominated the landscape for more than 60 million years, until the Devonian era, when vascular plants and trees began to grow taller and compete for light. Prototaxites also faced a new threat from the evolving insects, who started to feed on their tissues and spores. According to research by Dr. Francis Hueber of the Smithsonian, Prototaxites became extinct by the end of the Devonian era, about 360 million years ago.

About 65 million years ago, an asteroid strike killed 70 percent of all life on Earth. But it did not happen instantly. The lack of sunlight that followed the asteroid impact caused the plant life that survived the impact to rot quickly, creating the perfect conditions for fungi to thrive. When that happened, mammals had one key advantage over cold-blooded reptiles, the planet’s dominant life forms at the time. They’re warm. The reptiles were very vulnerable to fungal diseases, but a typical mammal, which keeps a temperature around the mid 30’s, creates a thermal barrier against fungi. The surviving mammals were the evolutionary ancestors of every mammal on the planet today, from civet cats to water buffalo to us. The warm-bloodedness of mammals, including ourselves, has evolved, partly, as a response to the pressure from fungus, which has made us seem to have cooked out fungal pathogens. Without that blackout, mammals may not have survived.

Fungi are not only decomposers, but also symbionts and parasites, and they interact with other organisms in different ways. Some fungi form mutualistic associations with plant roots, called mycorrhizae, that enhance the uptake of water and nutrients for the plants, and receive sugars in return. More than 90 percent of all plant species depend on mycorrhizal fungi for their growth and survival. Other fungi infect and control the behaviour of insects, such as the cordyceps fungi that make ants climb to high places and explode, releasing spores that infect more ants. Some fungi even manipulate the brains of mammals, such as rabies, which is actually a fungal parasite that causes aggression and biting in its hosts, facilitating its transmission.

Fungi also have many current and potential applications in various fields; such as medicine, biotechnology, agriculture, and environmental remediation. Fungi produce molecules that humans have not yet been able to synthesize in a lab, and we have much to learn from their chemistry. For instance, penicillin, the first antibiotic derived from a fungus, saved millions of lives during World War II and beyond. Other fungal compounds have been used to treat cancer, cholesterol, diabetes, and more. Fungi can also create biodegradable materials and packaging, such as mycelium, the vegetative part of fungi, that can be molded into different shapes and forms. Mycelium can also be used as insulation in buildings, as it is also biodegradable, non-toxic, and fire-resistant. It’s helped to clean up the environment by degrading pollutants, such as oil spills, pesticides, plastics, and more. Some fungi can even feed on radiation, as seen in Chernobyl, where a black fungus was found growing on the walls of the reactors.

Fungi may also have benefits for brain health, as some mushrooms contain antioxidants that can protect against oxidative stress and inflammation in the brain for mammals. Some studies have suggested that eating mushrooms may reduce the risk of cognitive decline and neurodegenerative diseases, as well as improve memory and learning. Fungi are truly remarkable and versatile, and they have much to offer to our health and well-being, and we’re only just touching the surface.

Ever since I was a child, I have been fascinated by fungi and mushrooms. I remember taking a survival course at a Christian camp when I was little, where they taught us how to recognize some edible and poisonous mushrooms. I enjoyed cooking and eating the safe ones, and I was amazed by the variety and beauty of fungi. I also learned how they could be both helpful and harmful, depending on the context. To this day, I am still wary of picking and eating wild mushrooms, as many toxic ones look very similar to edible ones. However, I have found a way to enjoy the benefits of mushrooms without the risks. At home, we have started taking a blend of Lion’s Mane, Reishi, Turkey Tail, Cordyceps, Shiitake, Chaga and Maitake; and we have noticed a positive difference in our mental and physical health. It may sound too good to be true, but there is scientific evidence to back up the claims of these medicinal mushrooms. Studies have shown that these mushrooms contain antioxidants, polysaccharides, and other compounds that can improve cognitive function, memory, mood, immune system, energy, and longevity. Even our cats seem to be more alert and playful after taking the mushroom blend. Fungi are truly remarkable organisms that have shaped life on Earth in many ways. They are the hidden heroes of our planet, and we owe them a lot. The more we learn about them, the more we appreciate their importance and diversity. Fungi are the kingdom that made our world and may just be the thing to save it yet.