Classification of OrganismsBIO 138 - Ch. 17

Ch. 17, section 1: Classification of Ch. 17, section 1: Classification of OrganismsOrganisms

--TaxonomyTaxonomy is the science of describing, is the science of describing, naming, and classifying organisms in an naming, and classifying organisms in an organized universally accepted way.organized universally accepted way.

-Over 2 million species have been classified -Over 2 million species have been classified and named.and named.

The History of ClassificationThe History of Classification

-Aristotle (384-322 BC): Grouped -Aristotle (384-322 BC): Grouped

organisms based on physical organisms based on physical

similarities; created binomial definition.similarities; created binomial definition.

-Carl Linnaeus (1707-1778): Developed -Carl Linnaeus (1707-1778): Developed classification system: kingdoms (3), classesclassification system: kingdoms (3), classes,,

order, genera, and species.order, genera, and species.

Linnaeus’s system was expanded to the Linnaeus’s system was expanded to the Modern System we use today:Modern System we use today:

1. Domain 1. Domain

2. Kingdom 2. Kingdom

3. Phylum (Division in plant kingdom.)3. Phylum (Division in plant kingdom.)

4. Class4. Class

5. Order5. Order

6. Family6. Family

7. Genus7. Genus

8. Species 8. Species

Naming Organisms:

Gaspard Bauhin (1560-1620) -created Binomial NomenclatureBinomial Nomenclature which is which is a naming system for newly discovered organisms that we still use today.

Example: Homo sapiens

Rules for naming organisms:Rules for naming organisms:

1. First letter of the first word, the genus identifier is 1. First letter of the first word, the genus identifier is capitalized; all other letters are lower case.capitalized; all other letters are lower case.

Example: GeococcyxExample: Geococcyx

2. All of the letters of the second word, the species 2. All of the letters of the second word, the species identifier, are lower case.identifier, are lower case.

Example: californianusExample: californianus

3. Putting the two words together, you must either 3. Putting the two words together, you must either underline the words or write them in italics.underline the words or write them in italics.

Example: Example: Geococcyx californianusGeococcyx californianus

Ch. 17, section 2: SystematicsCh. 17, section 2: Systematics

For modern day classification, scientists look beyond For modern day classification, scientists look beyond what they can physically see.what they can physically see.

Scientists use Scientists use SystematicsSystematics to classify organisms in to classify organisms in terms of their natural evolutionary relationships. terms of their natural evolutionary relationships.

Scientists look for similarities in:Scientists look for similarities in:embryosembryoschromosomeschromosomesproteinsproteinsDNA and RNADNA and RNA

Ch. 17, section 3: Ch. 17, section 3: The Three DomainsThe Three Domains

-Carl Woese, University of Illinois, 1977-Carl Woese, University of Illinois, 1977

1.1.EukaryaEukarya

2.2.Bacteria (bacteria, have peptidoglycan)Bacteria (bacteria, have peptidoglycan)

3.3.Archae (bacteria, no peptidoglycan)Archae (bacteria, no peptidoglycan)

-Domain comes before the Kingdom. -Domain comes before the Kingdom.

-For example: Humans are in the Domain Eukarya -For example: Humans are in the Domain Eukarya and Kingdom Anamalia.and Kingdom Anamalia.

The Kingdoms

The Six KingdomsThe Six Kingdoms

1. Protista- eukaryotic, nucleus, unicellular & multicellular, 1. Protista- eukaryotic, nucleus, unicellular & multicellular, microscopic, cell wall made of cellulose. Examples: microscopic, cell wall made of cellulose. Examples: amoeba, parameciumamoeba, paramecium

2. Fungi- eukaryotic, nucleus, unicellular & multicellular, cell 2. Fungi- eukaryotic, nucleus, unicellular & multicellular, cell wall made of chitin. Examples: molds, mildew, mushrooms. wall made of chitin. Examples: molds, mildew, mushrooms. These organisms absorb nutrients.These organisms absorb nutrients.

3. Plantae- eukaryotic, nucleus, unicellular & multicellular, 3. Plantae- eukaryotic, nucleus, unicellular & multicellular, cell wall made of cellulose, develop from embryos. cell wall made of cellulose, develop from embryos. Examples: plants.Examples: plants.

4. Animalia- eukaryotic, nucleus, multicellular, 4. Animalia- eukaryotic, nucleus, multicellular, no cell wall, develop from embryos. Examples: animals.no cell wall, develop from embryos. Examples: animals.

*Monera (prokaryotes)*Monera (prokaryotes)5. Archaebacteria- prokaryotic, no nucleus, unicellular 5. Archaebacteria- prokaryotic, no nucleus, unicellular bacteria, no peptidoglycans, cell wall, live in harsh bacteria, no peptidoglycans, cell wall, live in harsh environments.environments.

6. Eubacteria- prokaryotic, no nucleus, unicellular bacteria, 6. Eubacteria- prokaryotic, no nucleus, unicellular bacteria, has peptidoglycans, cell wall, types of bacteria we may has peptidoglycans, cell wall, types of bacteria we may encounter everyday.encounter everyday.

KingdomKingdom Animalia. Animalia. Man is part of the animal kingdom, the top Man is part of the animal kingdom, the top grouping. grouping.

PhylumPhylum Chordata. Chordata. This phylum consists of animals with spinal This phylum consists of animals with spinal cords. cords.

ClassClass Mammalia. Mammalia. Man is a mammal, a warm-blooded animal Man is a mammal, a warm-blooded animal who bears its young live. who bears its young live.

OrderOrder Primates. Primates. This order includes humans and all apes, This order includes humans and all apes, monkeys, gorillas, etc. monkeys, gorillas, etc.

FamilyFamily Hominidae. Hominidae. The hominids include man and his closest The hominids include man and his closest cousins, chimps and gorillas. cousins, chimps and gorillas.

GenusGenus Homo. Homo. The family of man, including our extinct The family of man, including our extinct predecessors, predecessors, Homo erectusHomo erectus and the neanderthals. and the neanderthals.

SpeciesSpecies sapiens sapiens. You and me.. You and me.

Domain EukaryaDomain Eukarya

Kingdom AnimaliaKingdom Animalia

Subkingdom MetazoaSubkingdom Metazoa

Phylum ChordataPhylum Chordata

Subphylum VertebrataSubphylum Vertebrata

Superclass TetrapodaSuperclass Tetrapoda

Class MammaliaClass Mammalia

Subclass TheriaSubclass Theria

Infraclass EutheriaInfraclass Eutheria

Order PrimatesOrder Primates

Suborder AnthropoideaSuborder Anthropoidea

Infraorder CatarrhiniInfraorder Catarrhini

Superfamily HominoideaSuperfamily Hominoidea

Family HominidaeFamily Hominidae

Subfamily HomininaeSubfamily Homininae

Tribe HomininiTribe Hominini

Genus HomoGenus Homo

Species sapiensSpecies sapiens

Subspecies sapiensSubspecies sapiens

-Classification of the Modern Human starting with Domain through Species: