Chapter 2Classification

Life Over Time

What is Classification? All Living Things are classified

– Classification means to arrange organisms into groups based on similarities or traits.

What are some examples of classification that we see everyday?

Early History of Classification

Aristotle- a Greek philosopher who observed living things.– Lived over 2000 years ago

Classified organisms as either plants or animals

Vocabulary Taxonomy- “taxis”= arrangement

– The science of naming and classifying organisms.

– Taxonomists use classification to organize living things on their similarities and differences.

Scientists collect physical and genetic evidence to classify species.

Kingdom- largest classification group –Aristotle created two Kingdoms:

Plants and Animals

–Today there are 6 Kingdoms

Classifying Species Years ago, scientist would classify

species according to behavior & appearances.

Scientist needed a system for organizing and naming organisms…

New system Carolus Linnaeus- Swedish physician

and naturalist who discovered and named ~4000 species.– Used appearance to classify species into

groups

– Created “two name” naming system that specifically identified ALL living things

Scientific Naming System Binomial Nomenclature- means

“Two Names” or Scientific Name

GENUS

First Name: Genus- a group of closely related

species–Example: Puma, Marbled Cats,

House Cat are classified in the… Genus: Felis

SPECIESSecond Name: Species- group of similar organisms that

reproduce among themselves.– Puma: Felis concolor – Marbled Cat: Felis marmorata– House cat: Felis domesticus

– Humans: Homo sapiens

FACT Over 1.5 million species have

been named and described.

However, it is estimated that as many as tens of millions of species have yet to be discovered…

Seven Levels of Classification

1. Kingdom-largest

2. Phylum

3. Class

4. Order

5. Family

6. Genus

7. Species-smallest

King Phillip Came Over For Good Spaghetti

Dichotomous Key- a tool used to help classify organisms based on their characteristics

Modern Classification Phylogeny- an

organism’s Evolutionary History – “Family

History” or “Family Tree”

Six Kingdom Names:1. Kingdom Eubacteria

- Strep throat

2. Kingdom Archaebacteria- Blue Green Algae

3. Kingdom Protista- One celled animals

4. Kingdom Fungi5. Kingdom Plant6. Kingdom Animal

Question? What are some reasons why scientists

classify things?

– Avoid Mistakes identifying species– Organisms with similar evolutionary

histories are classed together– Give descriptive info. about the species– Helps organize info. quickly and efficiently