Taxonomy “The Study of Classification”
What do you think? What does classification mean? Why is classification important? When do we use classification systems in our everyday lives? Books at the library, iPods and movies, even people!
Objectives Learn about the history of classification systems Recognize Linnaeus’ contribution Discuss classification keys and their usefulness Study Phylogenic trees and Cladograms Outline the 6 Kingdom system
What exactly is classification? Classification is a branch of Biology called Taxonomy. Taxonomy classifies based on similarities …but it wasn’t always this way!
Meet Aristotle (350 BC) Aristotle classified all living organisms as either a plant or an animal. He further classified animals by where they lived, and plants by their size.
Aristotle’s Classification Scheme ALL LIVING ORGANISMS PLANTS ANIMALS
PLANTS SHORT (Herbs) MEDIUM (Shrubs) TALL (Trees)
ANIMALS LAND WATER AIR
What are some problems with this classification system? Some animals live in more than one habitat during their lives. Most plants start small and grow larger.
These problems were recognized by Carolus Linnaeus “The Father of Modern Taxonomy”
Carolus Linnaeus Linnaeus was a Swedish botanist who lived in the 18th century. He decided to classify organisms based on their visible similarities and differences in structure.
Carolus Linnaeus Linnaeus made three huge contributions to modern taxonomy: Using structural criteria for classification Establishing the 7 taxa currently used. Created the Binomial Nomenclature
The 7 Taxa Kingdom Phylum Class Order Family Genus Species Pneumonic Device: King Phillip Came Over For Ginger Snaps Kingdom Phylum Class Order Family Genus Species Used in Scientific Names
7 Taxa Kingdom Phylum Class Order Family Genus Species
Did you notice? As you go down through the 7 taxa, you get more and more details about the organism you are looking at. Organisms get more and more similar from top to bottom.
Let’s Classify Us! Let’s classify a human: Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: Sapiens
Binomial Nomenclature Binomial nomenclature is a “two word” naming system. The first term describes the organisms genus while the second term describes the species.
Genus and Species Organisms placed in the same genus have similar structures (look the same). Organisms with the same species name are so similar they would be able to reproduce under normal circumstances to produce fertile offspring.
Binomial Nomenclature Scientific names are written in Latin and have something to do with the organisms characteristics or where they live. (Castor canadensis) (Ursus horribilus) Scientific names are written in italics or underlined. The first term is always capitalized while the second isn’t Example: Homo sapiens humans Homo sapiens H. sapiens
Examples of Scientific Names Canis lupus Wolf Canis familiaris Dog These organisms are structurally similar (same genus) but different species (cannot reproduce under normal circumstances to produce fertile offspring)
Scientific Names Equus caballus - horse Equus asinus – donkey When a donkey and a horse reproduce, their offspring is a mule, which is sterile.
Check out the Scientific Names