How is the entire earth not covered in slimy mold and other bacteria?



It takes 3 days or less for some food leftovers or even just wet spots on wood in room temperature to start growing a good amount of bacteria all over it, so how is it that like all of the ground and other organic material out in the elements aren’t completely covered in mold and algae after billions of years?

In: Biology

The earth is covered in microorganisms. On regular surfaces such as the ground, there is a limited amount of resources that support life. So microorganisms are there, just in lower numbers making it impossible to see them without a microscope. If you took a q-tip and swabbed a random surface and transferred it to a Petri dish with abundant food, you’d get a nice visible colony.

Because other animals exist and environments are a thing.

As you point out, you need wetness in order to grow these things, and the entire world isn’t wet all the time. Mold can’t grow just anywhere, it has to have particular conditions in order to survive. Further, other creatures eat the mold and bacteria and other creatures eat them in turn, and so on.

It is. They are everywhere. But other things eat mold and bacteria and there’s also the environment and things like weather…

The Earth IS covered in bacteria. Every surface in your home probably is too. But don’t worry, most of it is harmless.

Slime molds feed on decaying plant matter, so although they are abundant, they are mostly found in the soil.

It is. With the exception of some of the dryest and coldest parts of polar ice caps and very specially-sterilized labs, microorganisms coat every single square inch of Earth, from the highest mountains to the deepest trenches to the inside of your body. They’re not thick enough to have a noticeable texture on a “clean” surface, but they’re still there.

When it rains you inhale millions of spores and not know it. Your lungs just filter it out. Mold is everywhere and on everything. It just needs the right conditions to grow and spread. Temps above 50 degrees f and humidity above 55. Your house and everything in it are covered in mold. They are just dormant because it is too dry.