Classifying the Diversity

of Living Organisms

What is Taxonomy?• Taxonomy is the practice of

classifying organisms. • The Swedish botanist

Carolus Linnaeus developed the current taxonomic system in the 1700’s.

• He grouped organisms by their physical characteristics. Now, we also use genetic and biochemical information to classify organisms.

Carolus Linnaeus

Hierarchical Classification

• There are 7 different groups called taxa (singular - taxon) that are used to classify organisms

• Kingdom is the largest and most general taxon. Species is the smallest taxon – it includes only a single type of organism.

• Individuals of the same species can interbreed and produce fertile offspring.

The order of taxa from biggest to smallest

Name of Taxon Analogy

Biggest taxon Kingdom Country

Phylum Province

Class City

Order Neighbourhood

Family Street

Genus Street number

Smallest Taxon Species Apartment number

Remember this phrase: King Philip Came Over From Germany Swimming

Example Classification of

a Panther

Naming Organisms (Nomenclature)• Nomenclature means a naming system. Biologists use binomial

nomenclature to give every species a two-word scientific name. • The two part scientific name starts with the genus (first letter

capitalized) followed by the species name (all lower case letters).

Example) Common name – cat Scientific name – Felis domesticus

Why do we use scientific names?• Common names are not universal, whereas scientific

names are• Scientific names tell us about the organism’s

evolutionary history

HumanBox Elder Tree

BobcatCanadian lynx

Kingdom Animalia Plantea Animalia Animalia

Phylum/Division Chordata Anthophyta Chordata Chordata

Class Mammalian Dicotyledonae Mammalia Mammalia

Order Primates Sapindales Carnivora Carnivora

Family Hominidae Aceracae Felidae Felidae

Genus Homo Acer Lynx Lynx

Species sapiens nugundo rufus canadensis