Microbes
The Invisible Species Majority
For centuries, we only counted what we could see. As a result, we described about 2 million species, mostly insects, plants, and vertebrates.However, recent studies using molecular data (sequencing DNA directly from environmental samples) have completely upended these numbers.
Eukaryotes (Animals/Plants/Fungi): Current estimates suggest there are about 8.7 million eukaryotic species.
Microbes (Bacteria/Archaea): A landmark 2016 study (Locey and Lennon) estimated that Earth could be home to 1 trillion microbial species.
If this estimate is even remotely accurate, 99.999% of all species on Earth are microbes. We have discovered and described fewer than 0.001% of them.
They are everywhere. Soil, Water, Air, and other organisms.
So diverse and replicating by non-sexual self duplication. They start to blur the lines the artificial lines that we try and draw around organisms that we call species.
Apps and Learning Resources
Fantastic resource for Micorbial species
University of Utah Genetics great resource for getting an idea of how small microbes can be.
Please checkout the entire HHMI website. This is a link to their great virus explorer tool.
Considerations
The most basic living things on earth have found some of the most interesting and robust moethods for survival.
They show that being simple is a valid strategy and it has allowed them to be the most wide ranging group that lives in the the absolute harshest conditions that any living on out planet has been able to survive.
Microbes is not a taxonomically distinct category, but I believe a useful category to try and introduce the absolute wonders and oddities that can be found in the living things that are usually too small for any to notic ein their every day life.
Some can be dangerous to humans, but many are not. They comprise a world of living things that go unnoticed every day.
Also virus’s not classified as alive, but things can get more confusing or interesting when you talk about giant viruses.
Also Protists are the wild west of microbes. They refuse classification.