Taxonomy

With millions of species coexisting on planet Earth, there needs to be a way to name all of them. Taxonomy is the way different organisms are named, classified, and described. This system gives each species its unique name, making it easier to keep track of species. It was invented in the 18^th century by Swedish botanist Carolus Linnaeus, which only had two layers of classification and is known as the Linnaean system. Modern taxonomy has eight layers.

What are the eight taxonomic ranks?

The eight taxonomic ranks are:

1. Domain

2. Kingdom

3. Phylum

4. Class

5. Order

6. Family

7. Genus

8. Species

Domain in taxonomy

Domains are currently the newest addition to taxonomy after being added in the 1990s. This is known as the three-domain system because it split Bacteria and Archaea into their separate domains, known as prokaryotes. There are three different classifications under domains:

• Bacteria.

• Archaea (types of single-cell organisms that are similar to bacteria).

• Eukaryota (every other living thing that is not bacteria or archaeon, this domain includes us, aka humans).

Kingdoms in taxonomy

Kingdoms have one of the most controversial classification layers, with many changes over time. Some researchers ignore using kingdoms altogether because there is no agreement on kingdom classification.

The current breakdown of kingdoms are:

• Fungi

• Plantae

• Animalia

• Protista (any organism, not an animal, plant, or fungus)

• Archaea and Bacteria

Phylum in taxonomy

Phyla, the plural of phylum, are more specific than just using a kingdom for species classification and have been used since the 19th century. Phyla groups together species that are either evolutionarily related or have similar bodily traits.

Classes in taxonomy

Classes have been in use since Linneaus created them in the 18th century. As of right now, there are currently 108 different classes in the Animalia kingdom. These classes include Mammalia, consisting of mammals, and Reptilia, reptiles.

Order in taxonomy

Classes break down into orders. For example, in Mammalia, there are orders such as Cetaceans, which refer to whales, dolphins, porpoises, and Primates.

Families in taxonomy

Orders have different families within them. In our previous order of Primates, there are nine families. These families are Lemuridae, large lemurs, and Hominidae, humans.

Genus in taxonomy

Genera, the plural form of genus, is the first part of the scientific name for an organism. The scientific name is always italicised, with only the genus being capitalised.

Species in taxonomy

Species are the second part of the scientific name for an organism and are the only taxonomic rank that is never capitalised. In Homo sapiens, sapiens is the species name.

Examples of taxonomy

We will cover an example, a human classification.

Is there another way Organisms can be Classified?

There is another way organisms, especially their species, can be classified. This method is known as the IUCN (the International Union for Conservation of Nature) Classification of Species. Each species has its population assessed and is assigned one of nine labels:

• Not Evaluated

• Data Deficient

• Least Concerned

• Near Threatened

• Vulnerable

• Endangered

• Critically Endangered

• Extinct in the Wild

• Extinct

What do these Labels mean for Species?

These labels allow scientists to assess which species they need to prioritise with helping combat extinction. For example, species that are Endangered, Critically Endangered, and Extinct in the Wild will typically have breeding plans in captivity to help boost their numbers by releasing the offspring into the wild.