And Jesus said unto them, I am the bread of life: he that cometh to me shall never hunger; and he that believeth on me shall never thirst.”
John 6:35, Douay-Rheims
Now that we have become acquainted with what living things are and what they are made of, we are going to start our grand tour of the Kingdoms. As we have said, there are six Kingdoms: Archaea, Bacteria, Protists, Fungi, Plants, and Animals. I have no doubt that several of these names are familiar to my readers, but I would not be surprised if a few of them are completely unknown. In this chapter, we are going to visit the two kingdoms that are made entirely of microscopic creatures (those too small to be seen with the naked eye): the Kingdom of the Archaea (ar-key-uh) and the Kingdom of Bacteria.
Before we dive into the world of these amazing, tiny creatures, let us first consider that these are living things that cannot be seen except with a microscope, creatures known as microorganisms. Microscopes first gave people a glimpse into this tiny world about 450 years. Imagine that you might have been a medieval scholar or a Roman soldier or a worker on the pyramids and not known a thing about this part of creation. What a privilege it is to live at a time when we can behold so many wonders of the Creator!
Let’s imagine again that we are a robin (or did you choose a toucan?), flying over the kingdoms. We leave the villages of the Kingdom of Animals, teeming with life; soar over the Kingdom of Plants, verdant and peaceful; and then we spy in the distance two seemingly empty kingdoms. We see the fence around these two kingdoms with some lakes (one of them does appear to be a strange rainbow color), some soil, but otherwise there appears to be nothing. How strange. But, if we were able to fly down, getting smaller and smaller, into one of those lakes or into the soil or even into the air itself, we would see millions and billions and trillions of archaea and bacteria, nearly all of which are just one cell all by itself.
In the Kingdom of the Archaea, you would find creatures living in the most surprising of environments, for you see, archaea are extremophiles, they like to live in extreme environments. One of the lakes in the kingdom is astoundingly salty, like the Dead Sea, while another is boiling hot (that’s the brightly colored one). Part of the kingdom is freezing cold, while another is as dry as the most arid deserts. In each of these, vast numbers of archaea are found, living cozy little lives in the homes that are just right for them, even if the environment would kill any other living thing, such as toxic chemicals. Some of the archaea do live in more moderate environments, such as bogs or cow intestines or the ocean, but these often do strange things like produce methane (a smelly gas) or eat oil. Many new archaea are found every year because they live in such surprising places, and many are found in the most astonishing place of all – your own backyard (which is a strange place to find something that we usually see in the deep ocean and radioactive waste)!
If we fly over to the Kingdom of Bacteria and look in the ponds, gardens, and air (more typical homes, wouldn’t you say?), we would find many types of bacteria. I bet you have heard of bacteria before – maybe you got sick from one and had to take an antibiotic. It is certainly true that many of the things that make us sick are bacteria (we call those creatures germs), but the vast majority of bacteria are not harmful to humans and many of them are even our friends. You have many bacteria living in your body and on your skin (more than you have cells in your body!), and these bacteria help to fight off the harmful creatures that would make you sick. Like two armies facing off, the friendly bacteria and the germs fight in our bodies. Maintaining a healthy diet keeps our friends strong and victorious. Bacteria also help us make things, such as the bacteria that help make yogurt, pickles, and sourdough bread.