Living things can be grouped in a variety of ways. Classifications organise the variety of living things by features and characteristics.
Why do we need to classify living things?
- There are maybe 30 million species on our planet.
- There are nearly 18,000 animals and plants in the Eton Natural History Museum!
- It would be impossible if we just tried to describe and name each one individually.
- Although species can be very different from each other, many of them have similar features that allow us to put them into groups.
Animals are divided into two main groups. Animals that have a backbone are called vertebrates. Animals that don’t have a backbone are called invertebrates. These are then divided into smaller groups: vertebrates include mammals, birds, amphibians and fish. Invertebrates include insects and worms.
Let’s take an example and classify the Grey Squirrel. We’ll see there are many levels of classification. The top, or highest levels are Domain and Kingdom; these are the broadest categories. At the other end, we have living things grouped into species; these are the most specific categories.
A lot of the names for the classification groups seem strange, as they come from Latin, but they all have a specific meaning that relates to the features of the living things in that group.
Every animal and plant has a common name that we know it by; they also have a scientific name, which identify its classification. The Grey Squirrel’s scientific name is Sciurus carolinensis.
If you look at the full classification tree below, ‘Sciurus’ is the Genus, and ‘carolinensis’ is the Species. Scientific names are made up of the Genus and Species.
- Kingdom: Animalia, or “animal”
- Phylum: Chordata, or “has a backbone”
- Class: Mammalia, or “has a backbone and nurses its young”
- Order: Rodentia, or “has a backbone, nurses its young, and has long, sharp front teeth
- Family: Scuridae, or “has a backbone, nurses its young, has long, sharp front teeth, and has a bushy tail
- Genus: Sciurus, or “has a backbone, nurses its young, has long, sharp front teeth, has a bushy tail, and climbs trees
- Species: carolinensis , or “has a backbone, nurses its young, has long, sharp front teeth, has a bushy tail, and has brown fur on its back and white fur on its underparts
What is a species?
A species is a group of living things with very similar characteristics.. Individuals of the same species can reproduce to make more individuals of the same species. For example, two Grey Squirrels will reproduce a baby Grey Squirrel, just as two human beings make a human baby.