Take one step into your backyard, and you will be close to lichen. What is lichen? It is one of the oldest symbioses. What is a symbiosis you ask? It is an interaction between different organisms living in close physical contact. It’s a cooperative relationship.
Lichen surrounds us, but we don’t feel it. We see it, but we rarely stop and appreciate it. Lichen, while it may look like one species is in fact two different, intertwined species posing as one. This mutualistic behavior leads to various colors and shapes.
The first partner is a fungus that gives structure to the lichen. Fungi are made up of eukaryotic cells, meaning the internal structure contains organized compartments and also a membrane-bound nucleus that stores and protects the delicate genetic code. As such, fungi are heterotrophic organisms, obtaining their nutrients externally. Fungal food comes in the form of fixed carbon, which is often acquired through the process of decomposition. If a fungus cannot get sufficient food through decomposition, the fungus must get it through a symbiotic relationship with a partner. Enter partner #2.
Either green algae, categorized as a plant, or cyanobacteria, a group of bacteria, fulfill the needs of the fungus because they can both make carbon-based food through photosynthesis. They both have the ability to harness light energy from the sun and use it to make food in the form of glucose, or sugar (carbon source). This works out well for the fungus. This second partner provides an endless supply of glucose for the fungus, and in return, the fungus provides structure and protection.
It is this symbiotic relationship that allows these two species to live in harsh conditions. Lichen can live without rain for months, which explains why it is found in places like the arctic and the hottest deserts.
Look what can be accomplished by working together. Families and communities function a lot like lichen. As the green algae or cyanobacteria offer food and the fungus offers structure and protection, we all have much to offer one another. And we all have places where we lack that need to be filled up by others. What do you have to offer? What do you need from someone else? Don’t be afraid to give. Don’t be afraid to take.
The next time you are walking around in the woods or the yard, pay attention to the lichen growing on the rocks and trees. Appreciate it. There is more going on there than meets the eye. Thank God for that cool relationship. Let it remind, whether you are algae or fungus, you that you have a lot to offer the people around you. You have blind spots and you need others for life.
Let’s all make an intentional decision to be mutualistic symbionts in our own community.
Dragon Creek 