Understanding Understanding Classification Systems Classification Systems

Student Learning Student Learning Objectives:Objectives:

1.1. As a result of this lesson students As a result of this lesson students will understand the purpose for will understand the purpose for classifying living species.classifying living species.

2.2. As a result of this lesson students As a result of this lesson students will learn how to utilize biological will learn how to utilize biological classification systems.classification systems.

What is biological classification What is biological classification and why do we use it?and why do we use it?

Classification is the grouping of objects or Classification is the grouping of objects or information based on similarities.information based on similarities.

TaxonomyTaxonomy is the branch of biology that is the branch of biology that groups and names organisms based on groups and names organisms based on studies of their different characteristics.studies of their different characteristics.

Organizing helps you to understand better Organizing helps you to understand better and easier (just like in real life and easier (just like in real life ))

Classifications systems have been used for Classifications systems have been used for centuries, and have evolved dramatically centuries, and have evolved dramatically from the beginning.from the beginning.

Aristotle’s Classification SystemAristotle’s Classification System

Aristotle was a Greek philosopher developed the Aristotle was a Greek philosopher developed the first accepted system of biological classification.first accepted system of biological classification.

He classified all organisms into two groups; plants He classified all organisms into two groups; plants and animals. and animals.

He subdivided plants into three groups; herbs, He subdivided plants into three groups; herbs, trees, and shrubs depending on their size and trees, and shrubs depending on their size and structure of the plants. structure of the plants.

He divided animals according to where they spent He divided animals according to where they spent a great deal of time: on land, in air or water. a great deal of time: on land, in air or water.

What problems might exist for such a broad What problems might exist for such a broad grouping? grouping?

Linnaeus’s Classification Linnaeus’s Classification SystemSystem In the late eighteenth century a In the late eighteenth century a

Swedish botanist, Carolus Linnaeus Swedish botanist, Carolus Linnaeus (1707-1778), developed a method of (1707-1778), developed a method of grouping organisms that was more grouping organisms that was more useful than Aristotle’s. useful than Aristotle’s.

Linnaeus’s system was based on Linnaeus’s system was based on physical and structural similarities of physical and structural similarities of organisms. For example, he might organisms. For example, he might use similarities in flower parts as a use similarities in flower parts as a basis for classifying flowering plants. basis for classifying flowering plants.

Modern Classification Systems Modern Classification Systems use a two-word naming system use a two-word naming system

called called binomial binomial nomenclaturenomenclature

In this system the first word identifies the genus of In this system the first word identifies the genus of the organism, the second the species. The first the organism, the second the species. The first word is always capitalized and the second is not, word is always capitalized and the second is not, and is always found in italics. and is always found in italics. Homo sapiens,Homo sapiens, the the name for humans, is an example. name for humans, is an example.

Binomial nomenclatureBinomial nomenclature is used today to give is used today to give species their scientific names. species their scientific names. Binomial Binomial nomenclaturenomenclature is very important in naming living is very important in naming living species, because the language is always the same, species, because the language is always the same, regardless of the part of the world a person is in.regardless of the part of the world a person is in.

This allows for scientists to have a common This allows for scientists to have a common language to study these species.language to study these species.

Memorize the followingMemorize the following King King Philip Philip Cooks Cooks Onions Onions For For GuestGuest StrangersStrangers

Why?

All species are classified according to All species are classified according to biological classification systems that biological classification systems that categorize organisms broad at first categorize organisms broad at first and then into increasing more and then into increasing more detailed categories. detailed categories.

If we use this saying, we can take the If we use this saying, we can take the first letter of each word to remember first letter of each word to remember the classification system for all living the classification system for all living species.species.

King Philip Cooks Onions For Guest King Philip Cooks Onions For Guest StrangersStrangers

K stands for KingdomK stands for Kingdom P stands for PhylumP stands for Phylum C stands for ClassC stands for Class O stands for OrderO stands for Order F stands for FamilyF stands for Family G stands for GenusG stands for Genus S stands for SpeciesS stands for Species

In conclusion…In conclusion…

Learning about each kingdom lets you Learning about each kingdom lets you know how life is organized and know how life is organized and classified.classified.

Classification systems have gotten more Classification systems have gotten more complex over time.complex over time.

Every identified species can be classified Every identified species can be classified according to biological classifciation!according to biological classifciation!

Try performing classifications on your Try performing classifications on your own.own.