ORGANIZING LIFE’S DIVERSITY Chapter 17

Classification Ch. 17, Sec. 1

How Classification Began Classification Classification grouping objects or info based on similaritygrouping objects or info based on similarity Taxonomy Taxonomy branch of biology that classifies organismsbranch of biology that classifies organisms based on studies of different characteristics based on studies of different characteristics

Aristotle’s Classification System Aristotle Aristotle Greek philosopher who developed one of the first system of classification

Aristotle’s Classification System Aristotle Aristotle Grouped animals according to various characteristics, including habitat NOT based on evolutionary relationships. Bats, birds and flies grouped together. Whales and fish grouped together.

Linnaeus’s Classification System Carolus Linnaeus was an 18 th century Swedish botanist Carolus Linnaeus was an 18 th century Swedish botanist Developed a method for classifying organisms still used today. Developed a method for classifying organisms still used today. Based on physical and structural similarities of organisms. Based on physical and structural similarities of organisms. System called Binomial Nomenclature System called Binomial Nomenclature

Binomial Nomenclature Binomial Nomenclature 2 word naming system2 word naming system Always in LatinAlways in Latin Always italicized or underlinedAlways italicized or underlined Ex. Homo sapiens Ex. Homo sapiens Genus Genus 1 st word, capitalized1 st word, capitalized a group of closely related speciesa group of closely related species Ex. Homo Ex. Homo Species Species 2 nd word, lower case2 nd word, lower case describes a characteristic of the organismdescribes a characteristic of the organism Ex. sapiens (means “wise”) Ex. sapiens (means “wise”)

Scientific names and common names All organisms have a scientific name and a common name All organisms have a scientific name and a common name Common name = humanCommon name = human Scientific name = Homo sapienScientific name = Homo sapien The common name of an organism can vary from region to region. The common name of an organism can vary from region to region. Common NameCommon Name United States: house sparrow United States: house sparrow Spain: gorrion domestico Spain: gorrion domestico Holland: huismus Holland: huismus The scientific name of an organism is recognized globally. The scientific name of an organism is recognized globally. Scientific Name: Passer domesticusScientific Name: Passer domesticus

How Living Things Are Classified Organisms are ranked in taxa (categories) that range from broad to specific Organisms are ranked in taxa (categories) that range from broad to specific In order from: In order from: 1. Kingdom1. Kingdom 2. Phylum2. Phylum 3. Class3. Class 4. Order4. Order 5. Family5. Family 6. Genus6. Genus 7. Species7. Species King Phillip Came Over From Germany Sunday

The 6 Kingdoms Ch. 17, Sec. 2

How are evolutionary relationships determined? Evolutionary relationships are determined by: Evolutionary relationships are determined by: Structural similaritiesStructural similarities Homologous traits Homologous traits Breeding behavior Breeding behavior Geographical distribution Geographical distribution Chromosome comparisons Chromosome comparisons Biochemistry Biochemistry

Classification Models pg. 452 Phylogeny Phylogeny Based mainly on physical or genetic relationshipsBased mainly on physical or genetic relationships Cladistics Cladistics Based mainly on common ancestryBased mainly on common ancestry Cladogram Cladogram A branching diagram that models the phylogeny of a speciesA branching diagram that models the phylogeny of a species Similar to family treesSimilar to family trees

The Six Kingdomes Six kingdoms of organisms Six kingdoms of organisms Classified according to:Classified according to: Cellular structure Cellular structure Methods for obtaining energy Methods for obtaining energy

The Six Kingdoms Eubacteria (Prokaryotes) Eubacteria (Prokaryotes) Archaebacteria (Prokaryotes) Archaebacteria (Prokaryotes) Protists Protists Fungi Fungi Plants Plants Animals Animals

Prokaryotes Prokaryotes Microscopic, unicellular bacteria Microscopic, unicellular bacteria Lack membrane-bound organelles Lack membrane-bound organelles Some are heterotrophs, some are autotrophs Some are heterotrophs, some are autotrophs Oldest fossils are 3.4 billion years old. Oldest fossils are 3.4 billion years old. Archeabacteria Archeabacteria Several hundred species live in extreme environments Eubacteria Eubacteria Over 5000 species Some cause diseases

Protists Eukaryotes Eukaryotes lack complex organ systems lack complex organ systems Lives in moist environments Lives in moist environments Some are autotrophs, some are heterotrophs Some are autotrophs, some are heterotrophs Oldest fossils are 2 billion years old Oldest fossils are 2 billion years old

Fungi absorb nutrients from materials in the environment Heterotrophs that absorb nutrients from materials in the environment Help decompose, break down organic material Help decompose, break down organic material Oldest fossils 400 mya Oldest fossils 400 mya 50,000 known species 50,000 known species

Plants Photosynthetic eukaryotes Photosynthetic eukaryotes Multicellular Autotrophs Multicellular Autotrophs Oldest plant fossils more than 400 mya Oldest plant fossils more than 400 mya There are more than 250,000 species There are more than 250,000 species

Animals Multicellular heterotrophs Multicellular heterotrophs Cells are organized into tissues and organs Cells are organized into tissues and organs Oldest fossils are 600 mya Oldest fossils are 600 mya