Classifying Living Things

Chapter 2

Why Classify?

Quiz 2A

Classifyto arrange things into groups

Classification: the process of

grouping things based on their

similarities

Taxonomy

the science of classifying organisms into groups

(from Gk. taxis –

arrangement, order)

How does a good classification system help?

• Generalization: by learning about individual’s you may also learn about the whole group.

• It makes information about specific organisms easier to organize and find.

The Classification Hierarchy

First recorded classification of organisms was

attempted by Aristotle the Greek scientist and

philosopher.

Aristotle’s Classification System

Plants

HERBS - if they lacked woody parts

SHRUBS - if they had several short woody stems

TREES - one large woody stem .

Aristotle’s Classification System

Animals

FISH – swim

BIRDS - fly

LAND ANIMALS - walk

Aristotle’s Classification System

artificial classification system

based on appearance

(physical characteristics)

Aristotle's system was used for approximately 2,000 years.

(used into the 1600’s)

Carolus Linnaeus In the 1700's Carolus Linnaeus, a Swedish-naturalist, discovered

problems in the systematic arrangement for botany and began to

sketch his own classification method.

Carolus Linnaeus set forth a new classification system in his works

(books he wrote).

• Species Plantarum

• Systema Naturae

Species Plantarum

• published 1753

• forms the basis for plant classification

Systema Naturae

• published 1758

• forms the basis for animal classification

Linnaeus is known as the father of

modern biological classification or the

father of taxonomy.

Carolus Linnaeus

Linnaeus also established the modern scientific method of naming plants and animals.

His system is also an artificial classification system (based on physical characteristics).

It has more flexibility than the previous systems.

It is still used today.

Carolus Linnaeus

Linnaeus's 7 Basic Levels of Classification

His system has 7 basic levels (largest --->smallest)

Species are often divided into sub-species (or varieties – like dogs). Subphyla & subclasses may also be used.

kingdom

phylum (division)

class

order

family

genus

species

The more classification levels that two organisms

share, the more characteristics they

have in common.

As you move down the levels there are

fewer kinds of organisms in each

group.

Levels of Classification

Some classification systems have

an eighth level – domain –

that is a level higher than kingdom.

Organisms are placed into domains and kingdoms based on their cell type, their

ability to make food, and the number of cells in their bodies.

Unicellular prokaryotes

The "true bacteria". Examples: Enteric bacteria like E. coli, Salmonella typhus, Legionella, Heliobacter pylorii (cause of many ulcers), Neisseria gonorrhea (cause of gonorrhea), Nitrogen-fixing bacteria that are able to convert nitrogen gas into ammonia. Clostridium (tetanus, botulism).

also unicellular prokaryotes but they are found in some of the most extreme

environments on Earth (such as hot springs, very salty water, swamps, volcano

vents in the Pacific Ocean floor, and the intestines of cows)

Fungi

Protist

Plant

Animal

The Six Kingdoms

Kingdom Archaebacteria

Kingdom Eubacteria

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Kingdom Animalia

What about Humans?

Man is not an animal; he is God’s highest creation and

created in God’s image.

Christian Classification System?

Why don’t Christians invent a “Christian Classification System” that

would not be influenced by evolutionary bias? Any new system

that uses physical characteristics as the basis for classification would likely

group organisms quite similarly to the current system.

Christian Classification System?

There is a Christian classification system that has been proposed called

baraminology. The term baraminology comes from the Hebrew words bara, meaning “create,” and min, meaning

“kind.” Baraminology attempts to classify organisms according to their biblical kind.

Christian Classification System?

Since one of the primary functions of a classification system is to eliminate confusion regarding organisms, having a separate system

that is similar but not really parallel would likely add confusion rather than eliminate it. A more reasonable solution is for Christians to accept

the Bible as the source of all truth and reject any evolutionary bias found in the current system..