Classification/Taxonomy

Chapter 18

Why Classify?To study the diversity of life, biologists use a

classification system to name organisms &

group them in a logical manner.

TaxonomyDefined:

Discipline of classifying organisms and assigning each organism a

universally accepted name.In other words, naming things.

Why common names don’t workCommon names vary among languages.

Example:

United Kingdom – Buzzard refers to a hawk

United States – Buzzard refers to a vulture

Red-tailed Hawk Honey Buzzard Turkey Vulture

5

Aristotle 384 BC

• Classified organisms as either plants or animals

Carolus Linnaeus

• (1707 – 1778)

• Created the system of naming we use today.

• In taxonomy, a group or level of organization is called a taxonomic category or taxon.

Binomial Nomenclature• “Bi” means 2• “nomial” means number• “Nomen” means name• “Clature” means the system of

Defined:

In binomial nomenclature, each species is assigned a two-part scientific name.

8

Binomial Nomenclature

• Carolus Linnaeus• In binomial nomenclature, each species is

assigned a two-part scientific name. – The scientific name is always written in italics or

underlined. – The first word (the genus) is capitalized – The second word (the species) is lowercased.EX- Genus species or Genus speciesHumans- Homo sapien

Example of Binomial Nomenclature• Polar Bear is Ursus maritimus• Ursus: genus

Ursus contains 5 other kinds of bears

• maritimus: species The Latin word, maritimus, refers to the sea.

Polar bears often live on pack ice that floats in the sea.

10

Linnaeus's System of Classification

• A group or level of organization is called a taxonomic category, or taxon

• Linnaeus had 7-Kingdom “King Phylum PhillipClass CameOrder OverFamily ForGenus Great Species Spaghetti”

Definitions to know

• Genus: is a group of closely related species

• Species: Group of similar organisms that can breed and produce fertile offspring

• Family: Group of genera that share many characteristics

• Order: Group of similar families

• Class: Group of similar orders

• Phylum: Group of closely related classes

• Kingdom: Largest taxonomic group, consisting of closely related phyla.

Here We Go…Polar Bear

Species: maritimusGenus: Ursus

Family: UrsidaeOrder: CarnivoraClass: MammaliaPhylum: ChordataKingdom: Animalia

What do these mean?...lets see

What they mean

Species: maritimus (lives in marine environment)Genus: Ursus (kind of bear)Family: Ursidae (larger category of bears)Order: Carnivora (meat-eating animals)Class: Mammalia (warm-blooded, hair, & milk)Phylum: Chordata (vertebrates)Kingdom: Animalia (there are 6 kingdoms)

*Do NOT have to write*

How to remember:King Phillip Came Over For Green Salad

Kingdom Phylum Class Order Family Genus Species

Rules of the GameUniqueness: Every name has to be unique.

Universality: Zoologists have adopted, by international agreement, a single language to be used on a worldwide basis. All animals are given a generic (common name) and specific name in Latin (scientific name).

These names are in italics or are underlined (i.e. Homo sapiens).

Visuals

18

19

Checkpoint Questions:1. How are living things organized for study?2. Describe the system for naming species that

Linnaeus developed. 3. What are the seven taxonomic categories of

Linnaeus’s classification system? 4. Why do scientists avoid using common

names when discussing organisms? 5. What is significant about members of the

same species?