ClassificatioClassificationn

•There are There are 13 billion13 billion known species, but …known species, but …

•Represents Represents only 5% of only 5% of allall organisms that ever organisms that ever lived!lived!

•New organismsNew organisms are still are still being found and being found and identifiedidentified

Species of OrganismsSpecies of Organisms

What is Classification?What is Classification?

ClassificationClassification is the is the arrangement of organisms arrangement of organisms into orderly into orderly groupsgroups based based on their on their similaritiessimilarities

Classification is also known Classification is also known as as taxonomytaxonomy

Taxonomists Taxonomists are scientists are scientists that identify & name that identify & name organismsorganisms

Benefits of ClassifyingBenefits of Classifying

•Accurately & uniformlyAccurately & uniformly names organisms names organisms

•Prevents Prevents misnomersmisnomers (starfish & jellyfish aren't (starfish & jellyfish aren't really fish!) really fish!)

•Uses Uses same language same language (Latin or some Greek)(Latin or some Greek) for for all names all names

Sea”horseSea”horse”??”??

Confusion in Using Different Confusion in Using Different Languages for NamesLanguages for Names

Latin Names are Latin Names are Understood by all Understood by all

TaxonomistsTaxonomists

Early TaxonomistsEarly Taxonomists

•2000 years ago, 2000 years ago, AristotleAristotle was the first was the first taxonomisttaxonomist

•He divided organisms He divided organisms into into plants & animalsplants & animals

•He He subdividedsubdivided them them by their by their habitathabitat ---land, ---land, sea, or air dwellers sea, or air dwellers

Factors used to classify objects into a group are called CRITICAL ATTRIBUTES.

Early TaxonomistsEarly Taxonomists•John Ray, John Ray, a a

botanist, was the botanist, was the first to use Latin first to use Latin for namingfor naming

•Names were very Names were very long detailed long detailed descriptions descriptions telling everything telling everything about the plantabout the plant

Carolus LinnaeusCarolus Linnaeus

•18th century taxonomist

•Classified organisms by their structure

•Developed naming system which is still used today

Carolus LinnaeusCarolus Linnaeus

•Called the Called the “Father of “Father of Modern Taxonomy”Modern Taxonomy”

•Developed the modern Developed the modern system of naming known system of naming known as as binomial binomial nomenclaturenomenclature

•Two-wordTwo-word name (Genus name (Genus & species)& species)

Standardized Standardized NamingNaming

•Genus speciesGenus species

•Usually LatinUsually Latin

•ItalicizedItalicized in in printprint

•Capitalize Capitalize genusgenus, but NOT , but NOT speciesspecies

•UnderlineUnderline when when writingwriting

Turdus Turdus migratoriusmigratorius

American American RobinRobin

Binomial NomenclatureBinomial Nomenclature

Corn• Plantae

• Spermatophyta      

• Magnoliophyta

• Liliopsida

• Cyperales

• Poaceae

• Zea (Genus)

• mays (species)

• Pioneer 32 D 99

Rules for Naming OrganismsRules for Naming Organisms

•The The International Code for International Code for Binomial Nomenclature Binomial Nomenclature contains contains the rules for naming organismsthe rules for naming organisms

•All names must be approved by All names must be approved by International Naming CongressInternational Naming Congress (International Zoological (International Zoological Congress)Congress)

•This This prevents duplicatedprevents duplicated names names

Classification GroupsClassification Groups

•TaxonTaxon ( ( taxataxa-plural) is a -plural) is a category into which related category into which related organisms are placedorganisms are placed

•There is a There is a hierarchyhierarchy of of groups (taxa) from broadest groups (taxa) from broadest to most specificto most specific

•Domain, Kingdom, Phylum, Domain, Kingdom, Phylum, Class, Order, Family, Class, Order, Family, Genus, Genus, speciesspecies

Classification: Day 2

Criticalattributes canbe used tocategorizeobjects

What word do these have in common?

stickhairball

manwheelhigh

motionpokedown

waterpensoda

backlightshort

keywallprecious

steadycartslow

coolhousefat

stoolpowderball

pin chair slow

fountain stop stone

gocat foot

•BroadestBroadest, most inclusive , most inclusive taxontaxon

•ThreeThree domains domains

•Archaea and EubacteriaArchaea and Eubacteria are are unicellular prokaryotes (no unicellular prokaryotes (no nucleus or membrane-bound nucleus or membrane-bound organelles)organelles)

•EukaryaEukarya are more complex are more complex and have a nucleus and and have a nucleus and membrane-bound organellesmembrane-bound organelles

DomainsDomains

ArchaeaArchaea live in live in harsh environmentsharsh environments and and may represent the first cells to have may represent the first cells to have evolved.evolved.

Sewage Sewage treatment treatment

plants, plants, thermal thermal

vents, etc.vents, etc.

EubacteriaEubacteria, some of which , some of which cause human diseases, are cause human diseases, are present in almost present in almost all habitatsall habitats on earth.on earth.

Many bacteria are important Many bacteria are important environmentally and environmentally and

commercially.commercially.

Example: Example: E. coli E. coli live in live in the the intestineintestines of s of animalsanimals

Economic importance of bacteria include

1) Medication – insulin 2) Food production – cheese,

sauerkraut3) Forensics – increase suspect

DNA samples

Diseases caused by bacteria include

1) tuberculosis2) meningitis3) food poisoning (botulism)4) strep throat (staphylococcus)

Domain Eukarya is Domain Eukarya is Divided into 4 KingdomsDivided into 4 Kingdoms

•ProtistaProtista (protozoans, algae…) (protozoans, algae…)

•FungiFungi (mushrooms, yeast …) (mushrooms, yeast …)

•PlantaePlantae (multicellular plants) (multicellular plants)

•AnimaliaAnimalia (multicellular animals) (multicellular animals)

Hierarchy of Hierarchy of Taxonomic GroupsTaxonomic Groups

DomainKingdom

Phylum (Division – used for plants)

Class Order Family

Genus Species

BROADEST BROADEST TAXONTAXON

KKinging

PPhilliphillip

CCameame

OOverver

FFromrom

GGreatreat

SSpainpain

Protista (protists)Protista (protists)

•Most are Most are unicellularunicellular

•Some are Some are autotrophic autotrophic (plant-like)(plant-like), , while others while others are are heterotrophic heterotrophic (animal-like)(animal-like)

•ex: ex: paramecia, paramecia, ameba, diatomsameba, diatoms

FungiFungi •Multicellular,Multicellular, except yeastexcept yeast

•Absorptive Absorptive heterotrophsheterotrophs (digest food (digest food outside their outside their body & then body & then absorb it)absorb it)

•Cell walls Cell walls made of made of chitinchitin

PlantaPlantaee

•MulticellularMulticellular

•AutotrophicAutotrophic

•Absorb Absorb sunlight sunlight to to make glucose make glucose – – PhotosynthesiPhotosynthesiss

•Cell walls Cell walls made of made of cellulosecellulose

AnimaliaAnimalia

•MulticellularMulticellular

•Ingestive Ingestive heterotrophsheterotrophs (consume (consume food & digest food & digest it inside their it inside their bodies)bodies)

•Feed on Feed on plants or plants or animalsanimals

TaxonTaxon

•Each genus contains a Each genus contains a number of similar species, number of similar species, with the exception of with the exception of HomoHomo which only contains which only contains modern humans (modern humans (Homo Homo sapiens)sapiens)

•Classification is based on evolutionary relationshipsevolutionary relationships

Basis for Modern Basis for Modern TaxonomyTaxonomy

•Homologous structuresHomologous structures (same structure, (same structure, different function)different function)

•Similar Similar embryoembryo developmentdevelopment

•Similarity in Similarity in DNA, RNADNA, RNA, , or or amino acidamino acid sequences sequences (proteins)(proteins)

Homologous Structures Homologous Structures show similarities in show similarities in mammals.mammals.

SimilaritiSimilarities in es in VertebratVertebrate e EmbryosEmbryosDeveloping young are immersed in an aquatic environment whether in an egg or a uterus, so similarities exist.

CladogramCladogramDiagram showing how organisms are related Diagram showing how organisms are related

based on based on shared, derived characteristicsshared, derived characteristics such as feathers, hair, or scalessuch as feathers, hair, or scales

Dichotomous KeysDichotomous Keys

•Used to identify Used to identify organismsorganisms

•Characteristics given in Characteristics given in pairspairs

•Read both Read both characteristicscharacteristics and and either go to another set either go to another set of characteristics of characteristics OROR identify the organismidentify the organism

Example of Dichotomous Example of Dichotomous KeyKey

1a Tentacles present – Go to 21a Tentacles present – Go to 2

1b Tentacles absent – Go to 31b Tentacles absent – Go to 3

2a Eight Tentacles – Octopus2a Eight Tentacles – Octopus

2b More than 8 tentacles – 32b More than 8 tentacles – 3

3a Tentacles hang down – go to 3a Tentacles hang down – go to 44

3b Tentacles upright–Sea 3b Tentacles upright–Sea AnemoneAnemone

4a Balloon-shaped body–4a Balloon-shaped body–JellyfishJellyfish

4b Body NOT balloon-shaped - 54b Body NOT balloon-shaped - 5