A word everyone knows, yet no-one fully understands.

Intro

Life is hard. Very hard. So all living creatures form partnerships to make life a little easier. Some good for both, some good for one and bad for the other. So to weather the storm we call life, it is important to find the right partner. Not partner as in love and marriage and all that, although that is important too. Partner as in working relationships to survive. As most of us know, working together is hard. Finding a way to not only tolerate, but benefit each other, that is the secret to a good partnership. As always, nature provides some great examples of how to do, or how to don’t.

Types of symbiosis

Mutualism

The one everyone likes. All parties involved benefit. It is the ideal image of symbiosis. Two or more creatures work together in an equal partnership. Equal might not be completely correct. In nature, there is no real equality. It is a relationship where all parties benefit more than they suffer. Yes, that might be the right description.

A good example are lichen, a partnership between a fungi and either a cyanobacteria or an algae. Two separates types of life working together, trying to be a plant. Able to do photosynthesis because of the cyanobacteria/algae, while the fungal mycelium functions as a root/ protective system. Even though they work together, live together and grow together, it is still a combination of two very different forms of life. This means they can procreate together. What they can do, to keep the relationship going, is a form on asexual reproduction. They make ready-to-go-packages that have both species already in it, and then spread those. Sometimes adjoining the parent organism, sometimes over a small distance. For sexual reproduction, the fungi let their spores be taken by the wind, and then when those spores come in contact with a compatible algae can form a new community.

Interesting about lichen is that a lot of species are very sensitive to air-pollution. If there is lots of them, you are probably surrounded by clean air. So enjoy it.

Commensalism

This one is a little less wholesome, but still not evil. In this type of partnership, one creature benefits, and the other doesn’t really benefit or suffer from it. It’s a very one-sided relationship. However toxic this is in relationships between humans, it doesn’t really harm the host in this case. Sometimes they just lose a bit of charm. Or gain some, depending on your perspective.

Humpback whales. Yes, from the green and yellow spots on rocks and walls, all the way to the depths of the ocean. I am taking you everywhere. These whales, badass as they look, are being taken advantage of. Not in a weird way. In a harmless, yet quite obvious way. Imagine a humpback whale. Black everywhere, except for some white dots on their head, chin and sometimes fins. Those white dots are not part of them when they are born. They come in later. Those are barnacles. Because barnacles are sessile (a fancy word for non-mobile) creatures, they hitch a ride on the whale’s face. Now why would they do that? Some people think it is because barnacles have dreams of seeing the world, and living in a whale’s chin flaps is the only way to do so when you can’t move yourself. Another, more scientific theory is that it’s because barnacles are filter feeders and the whales are an easy way to get to fertile waters. The barnacles pick a spot on the head and chin, probably because the water flow there is continuous and it’s close to whale leftovers. Easy meals for life.

Of course, believe what you want to. I like my barnacles like I like my sleep, filled with hopes and dreams.

Parasitism

Now this is the evil one. A form of partnership where one does all the work and the other benefits from it. Much like group works in high school. Sometimes the host even dies because of the relationship, a little more unlike high school.

As always in nature, there are different degrees of evil. There are hemiparasites, they only partly need their host to survive. A good example is mistletoe. They can do photosynthesis, yet choose to also steal nutrients and water from trees. Maybe that actually makes it more evil. It could possibly rely on itself, but it still steals another tree’s life-juice.

If we step it up a little. There are full parasites, but not yet fatal. These are the ones profiting from their host, while the host suffers. Like a tapeworm, or an unborn baby (just kidding, even though it is a similar type of living). They feed on whatever their host eats and steals it away for their own benefit. This means the host loses precious nutrients and gets weaker, or eats more. Although the host experiences some drawbacks, it is able to keep living. It just needs to work harder to keep their body going.

The next level is of course complete parasites that also kill their host. Why would you kill the thing feeding you? Why would you kill your host? Easy, procreation. As you will find out, in nature, almost everything is because of procreation. The host is either used an incubator and food supply for babies, or the corps of the host is an actual parasite transmitter. Like a parasitoid wasp, laying eggs in a living animal in whom the egg hatches and the larva starts eating its way out. Not the most pleasant way to die, but for some, the only way to experience giving life.

Hive Mind

No, I am not talking about bees. I will be talking about a super organism so big you wouldn’t be visible on the photo if you were to take a picture with it. A brain so huge, it wouldn’t blow your mind, it would erupt it. I am talking about forests. What? How? No worries, I shall explain myself. Forests are collections of trees and plants, and often some animals and fungi inhabit them. That is of course only what you see. Above the ground there is lots of wood and leafs and dead wood and living animals and living plants and berries. You know, all the good stuff. Below ground however, there is a magical kingdom of earth-dwelling and -puncturing creatures. Not talking about a mole, a rat or rabbits. I am talking about the mysterious white threads that are seemingly everywhere. They are called mycelia, and they are fungi. Those white ropey things are filaments and they connect fungi with other fungi, but most importantly with plants.

Mycelia form a whole connectivity network, often called the wood wide web. This web connects neighbouring trees, plants and other fungi. Most plants and trees have a mutualistic relationship with fungi. They give the fungi carbon, and the fungi help the plant get water, minerals and sometimes nitrogen. Some groups of symbiotic fungi even protect their hosts against bacteria or parasitic fungi. Not only does this help plant life grow better, it also makes them able to communicate. The mycelia also function as a form of telephone wires. Plants can exchange warning and distress signals through fungi. If necessary, they can even exchange resources.

This means that because all those plants and trees have symbiotic relationships with different fungi and in turn those fungi having multiple host plants and trees, there is a huge web for information and resource exchange. The forest functions as one huge brain. Makes your brain feel a little tiny probably. But remember, we can walk, so we win.

Cordyceps

Why make a separate paragraph about these fungi. It’s simple really, they are cool. Even laboulbeniologists (biologists throwing their life away studying Laboulbeniales) say it’s a better use of your time to watch cordyceps (Laboulbeniales are also a parasitic group of fungi, only less cool and less well-known). So Cordyceps it is. The zombie-makers. The OG zombifiers, before the rise of tiktok and schools. These fungi infect an insect, grow inside of it, drug it and basically puppeteer it into spreading their spores. Some use hallucinogenics to make the insect climb to the highest point possible and face the opposite of the dominant wind direction.

Even though the series “The Last of us” looks cool and does have a scientific foundation, we won’t be turning in to zombies soon. Evolution doesn’t happen that fast. Never say never, but before humans, there would probably be another mammal species infected. For now, let’s hope the cordyceps stays within insects.

Summary

What have we learned?

That I have a lot of pictures of mushrooms and none of whales or intestines.

Neither humans, nor dolphins have the biggest brain. Forests are the biggest brain. No need to fear their intelligence however, they haven’t figured out how to walk yet.

Parasites come in all shapes and sizes. Either fear everything or nothing, in between is just useless.

Working together is natural. Nature is hard. Ergo, working together is hard. Life is even harder though, so let’s at least give it a go.

Not all symbiotic relationships are all rainbows and sunshine. Some are very much monochromatic arches and a dead leprechaun.

Thanks for reading. I hope you enjoyed it and you come back on Friday for the creature of the week.

Here is a link if you are interested in Laboulbeniales.