What is an Animal?

Taxonomy

Taxonomy is the system of classification we use as scientists to identify all creatures. This system starts in very broad classifications and works its way down to more specific classifications. The order of classifications is as follows: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. A common way of remembering the order of these classifications is by remembering the phrase Dear King Phillip Came Over For Good Spaghetti. 

There are only three domains that are commonly recognized: Eukarya, Bacteria, and Archaea. Domain bacteria houses, as its name implies, bacteria. Archaea is full of single celled organisms that lack a nucleus. The most important one for the purposes of this blog, is Eukarya. This where more complex, living organisms– like humans– are classified into. 

Kingdom

The kingdom that humans and other animals are classified under is Kingdom Animalia. To be classified in this kingdom we all need to have the following shared traits. 

  • Multicellular (we are more than a single, free floating cell), eukaryotic (our domain) organisms
  • Lack chlorophyll (something found in plants) and a cell wall

Animals are then broken further down into more specific groups. The importance of this is as we go down the levels, the animals in each group share more and more characteristics. There are plenty of animals that may not look like what the mainstream definition of animal is, but still fit into this category because they have the above traits. Things, for example, like sponges and corals. 

Morphological Classification

Once upon a time, humans used to classify things into groups based on their appearance. This was known as morphological classification. This fell out of favor with modern day taxonomists because with modern day DNA analysis technology, we found that just because something likes alike, doesn’t mean it is related. 

For example, a shark and a dolphin live in the same habitat (the ocean) and for all intents and purposes look pretty similar. We know now though, that one is a mammal and one is a fish. This means that a dolphin is warm blooded, has mammary glands, and breathes air. Sharks lay eggs (sometimes internally, sometimes externally), have gills to absorb oxygen through the water, and are cold blooded. 

Animal Science

There is so much more that goes into how we classify animals, but this is a good general introduction to why things are the way they are. If you are interested in this subject, consider diving into animal science with our education department by booking an educational program for you and your family today. Simply send over an email to education@sawgrassnaturecenter.org to get started.