“Why do scientists classify?”

Imagine that you live in a tropical rain forest and are responsible for getting your own food, shelter, and clothing

from the forest. What do you need to know to survive?

1) If you are going to survive, you willneed to know which plants you can eat and which are poisonous.

2) You will need to know which animals to eat and which may eat you.

You will need to organize the living things around you into categories, or

classify them.

Think about an elephant.  Develop a mental image of it.  How would you describe it to someone who

has never seen one?  Take a moment to consider carefully . . .

Classification

• Is the arrangement of organisms into groups based on their similarities.

ClassificationHistory

• Greek• Began with Aristotle

in 384-322 B.C• Animals separated in

groups by blood, way of life, and body shape.

Classification History

• English• John Ray created, in 1600’s,

the basic unit of classification using diff. species.

Carolus Linnaeus

• Swedish• Doctor and botanist• Created

taxonomy/classification 1753

“Why Classify?”

• Classifying living things makes it easier for biologists to find the answers.

• To see how organism are related.

How is a cat like a tiger?

Taxonomy

• Is the science of identifying, classifying, and naming living things.

• Based on a common ancestor.

Ex. Platypus, bear, lion, cat = Mammalia

BranchingDiagrams• Show the

characteristics that link animals to a common ancestor.

Levels of Classification

• King Phillip came over for grape soda.

Kingdom

PhylumClass

OrderFamily

Genus

Species

Classification level

NameCharacterized by:

Domain EukaryaNucleus, organelles

Kingdom AnimaliaIngests food, multicellular, no cell wall

Phylum Arthropoda

Hard exoskeleton, paired legs, segmented body

Class InsectaTerrestrial, six legs, antennae

Order Diptera Two-winged

Family Drosophilidae  

Genus Drosophila  

Species D. melanogaster Common fruit fly

Scientific Names

• In Latin/Greek -Universal naming

(so everyone understands)

• Have 2 parts

Ex. Indian Elephant =

Elephas maximus

genus species

Indian Elephant = Elephas maximus

Tyrannosaurus rex

Genus

“tyrant lizard

Species

“king”

Dichotomous Key• Helps identify unknown organisms using pairs of

statements or questions.

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“So,why do scientists classify?”