ORGANIZING LIFE’S ORGANIZING LIFE’S DIVERSITYDIVERSITY

Chapter 17Chapter 17

ClassificationClassification

Ch. 17, Sec. 1Ch. 17, Sec. 1

How Classification BeganHow Classification Began

ClassificationClassification• grouping objects or info based on grouping objects or info based on

similaritysimilarity TaxonomyTaxonomy

• branch of biology that classifies branch of biology that classifies organisms organisms

based on studies of different characteristicsbased on studies of different characteristics

Aristotle’s Classification SystemAristotle’s Classification System

AristotleAristotle • Greek philosopher Greek philosopher

who developed one who developed one of the first system of the first system of of classificationclassification

Aristotle’s Classification SystemAristotle’s Classification System

AristotleAristotle • Grouped animals Grouped animals

according to various according to various characteristics, characteristics, including habitatincluding habitat

• NOT NOT based on based on evolutionary evolutionary relationships.relationships.

Bats, birds and flies Bats, birds and flies grouped together.grouped together.

Whales and fish Whales and fish grouped together. grouped together.

Linnaeus’s Classification SystemLinnaeus’s Classification System

Carolus Linnaeus was Carolus Linnaeus was an 18an 18thth century century Swedish botanistSwedish botanist

Developed a method Developed a method for classifying for classifying organisms still used organisms still used today. today.

Based on physical and Based on physical and structural similarities structural similarities of organisms. of organisms.

System called System called Binomial Binomial NomenclatureNomenclature

Binomial NomenclatureBinomial Nomenclature• 2 word naming system2 word naming system• Always in Latin Always in Latin • Always italicized or underlinedAlways italicized or underlined

Ex. Homo sapiensEx. Homo sapiens GenusGenus

• 11stst word, capitalized word, capitalized• a group of closely related speciesa group of closely related species

Ex. Ex. HomoHomo SpeciesSpecies

• 22ndnd word, lower case word, lower case• describes a characteristic of the organismdescribes a characteristic of the organism

Ex. Ex. sapienssapiens (means “wise”) (means “wise”)

Scientific names and common Scientific names and common namesnames

All organisms have a All organisms have a scientific scientific namename and a and a common namecommon name• Common name = humanCommon name = human• Scientific name = Homo Scientific name = Homo

sapiensapien

The common name of an The common name of an organism can vary from organism can vary from region to region. region to region. • Common NameCommon Name

United States: house sparrowUnited States: house sparrow Spain: gorrion domesticoSpain: gorrion domestico Holland: huismus Holland: huismus

The scientific name of an The scientific name of an organism is recognized organism is recognized globally.globally.• Scientific Name: Passer Scientific Name: Passer

domesticus domesticus

How Living Things Are ClassifiedHow Living Things Are Classified Organisms are ranked in Organisms are ranked in taxa (categories)taxa (categories)

that range from broad to specificthat range from broad to specific In order from:In order from:

• 1. Kingdom 1. Kingdom • 2. Phylum2. Phylum• 3. Class3. Class• 4. Order 4. Order • 5. Family 5. Family • 6. Genus 6. Genus • 7. Species7. Species

King Phillip Came Over From Germany Sunday

The 6 KingdomsThe 6 Kingdoms

Ch. 17, Sec. 2Ch. 17, Sec. 2

How are evolutionary relationships determined?How are evolutionary relationships determined?

Evolutionary relationships are Evolutionary relationships are determined by:determined by:• Structural similaritiesStructural similarities

Homologous traitsHomologous traits

Breeding behaviorBreeding behavior Geographical distributionGeographical distribution Chromosome comparisonsChromosome comparisons BiochemistryBiochemistry

Classification Models pg. 452Classification Models pg. 452

PhylogenyPhylogeny• Based mainly on physical or genetic Based mainly on physical or genetic

relationshipsrelationships Cladistics Cladistics

• Based mainly on common ancestryBased mainly on common ancestry CladogramCladogram

• A branching diagram that models the A branching diagram that models the phylogeny of a speciesphylogeny of a species

• Similar to family treesSimilar to family trees

The Six KingdomesThe Six Kingdomes

Six kingdoms of organismsSix kingdoms of organisms• Classified according to:Classified according to:

Cellular structureCellular structure Methods for obtaining energyMethods for obtaining energy

The Six KingdomsThe Six Kingdoms

Eubacteria (Prokaryotes)Eubacteria (Prokaryotes) Archaebacteria (Prokaryotes)Archaebacteria (Prokaryotes) ProtistsProtists FungiFungi PlantsPlants AnimalsAnimals

ProkaryotesProkaryotes Microscopic, unicellular bacteriaMicroscopic, unicellular bacteria Lack membrane-bound organellesLack membrane-bound organelles Some are heterotrophs, some are Some are heterotrophs, some are

autotrophsautotrophs Oldest fossils are 3.4 billion years Oldest fossils are 3.4 billion years

old. old. ArcheabacteriaArcheabacteria

• Several hundred speciesSeveral hundred species• live in extreme environmentslive in extreme environments

EubacteriaEubacteria• Over 5000 species Over 5000 species • Some cause diseasesSome cause diseases

ProtistsProtists EukaryotesEukaryotes lack complex organ systemslack complex organ systems Lives in moist environmentsLives in moist environments Some are autotrophs, some are Some are autotrophs, some are

heterotrophsheterotrophs Oldest fossils are 2 billion years old Oldest fossils are 2 billion years old

FungiFungi Heterotrophs that absorb nutrients absorb nutrients

from materials in the environmentfrom materials in the environment Help Help decomposedecompose, break down organic , break down organic

materialmaterial Oldest fossils 400 myaOldest fossils 400 mya 50,000 known species 50,000 known species

PlantsPlants

Photosynthetic eukaryotesPhotosynthetic eukaryotes Multicellular AutotrophsMulticellular Autotrophs Oldest plant fossils more than 400 Oldest plant fossils more than 400

myamya There are more than 250,000 speciesThere are more than 250,000 species

Animals Animals

Multicellular heterotrophsMulticellular heterotrophs Cells are organized into tissues and Cells are organized into tissues and

organsorgans Oldest fossils are 600 myaOldest fossils are 600 mya