Taxonomy – the science of classifying organisms

Why do we need a system to classify and name organisms?
Here are some common names:

spider monkey sea monkey sea horse
gray wolf firefly crayfish
mud puppy horned toad ringworm
black bear jellyfish  spiny anteater

These names can vary by region and can also be misleading. Is a sea horse really a horse?

Naming Organisms:

Organisms have common & scientific name -all organisms have only 1 scientific name
-usually Latin or Greek
-developed by Carolus Linnaeus

This two-word naming system is called…..

Binomial Nomenclature

-written in italics (or underlined)
-1st word is Capitalized –Genus
-2nd word is lowercase —species

Examples: Felis concolor, Ursus arctos, Homo sapiens, Panthera leo , Panthera tigris.   These can also be abbreviated as  (P. tigris or P. leo)

Linneaus also devised the system we use to organize animals.  This system uses large groups divided into subgroups (like the way you organize folders on your computer)

Kingdom —  Phylum — Class — Order — Family — Genus — Species

Human Lion Tiger Pintail Duck
Kingdom Animalia Animalia Animalia Animalia
Phylum/Division Chordata Chordata Chordata Chordata
Class Mammalia Mammalia Mammalia Aves
Order Primate Carnivora Carnivora Anseriformes
Family Homindae Felidae Felidae Anatidae
Genus Homo Panthera Panthera Anas
Species sapiens leo tigris acuta

Each organism has a group and subgroups. The organisms with the most similar groups will be most closely related.  Note that both the lion and the tiger are in the same genus, but are considered to be separate species.

There are currently 6 kingdoms – organisms are placed into the kingdoms based on the number and type of cells they have,  and their nutritional needs.

of Cells
energy cell
archaebacteria unicellular some
autotrophic, most chemotrophic
prokaryote “extremophiles”
eubacteria unicellular autotrophic
and heterotrophic
prokaryote bacteria,
E. coli
fungae most
heterotrophic eukaryote mushrooms,
plantae multicellular autotrophic eukaryote trees,
animalia multicellular heterotrophic eukaryote humans,
insects, worms
protista most
or autotrophic
eukaryote ameba,
paramecium, algae

Additional Links on Taxonomy

Build a CladogramTree of Life Web Project