Classification/TaxonomyClassification/Taxonomy

Chapter 18Chapter 18

Why Classify?Why Classify?

To study the diversity of life, biologists use a To study the diversity of life, biologists use a

classification system to name organisms,classification system to name organisms,

group them in a logical manner, and studygroup them in a logical manner, and study

evolutionary relationships.evolutionary relationships.

TaxonomyTaxonomyDefinedDefined::

Discipline of classifying Discipline of classifying organisms and assigning each organisms and assigning each

organism a universally organism a universally accepted name.accepted name.

In other words, naming things.

Why common names don’t workWhy common names don’t workCommon names vary among different languages.Common names vary among different languages.

CatCat Arabic: quttahArabic: quttah

Czech: kockaCzech: kocka

French: chatFrench: chat

German: katzeGerman: katze

Japanese: nekoJapanese: neko

Russian: kotchkaRussian: kotchka

Spanish: gatoSpanish: gato

Why common names don’t workWhy common names don’t workCommon names vary among different countries.Common names vary among different countries.

Example:Example:

United Kingdom – Buzzard refers to a hawkUnited Kingdom – Buzzard refers to a hawk

United States – Buzzard refers to a vultureUnited States – Buzzard refers to a vulture

Red-tailed Hawk Honey Buzzard Turkey Vulture

Why common names don’t workWhy common names don’t workMany species have several common names.Many species have several common names.

Sand tiger Sand tiger sharkshark

Sand sharkSand shark

Gray nurse Gray nurse sharkshark

Why common names don’t workWhy common names don’t work

Dolphin Dolphin

Mahi mahi Turciops truncatus

Same common name used for different species

First Attempt to ClassifyFirst Attempt to Classify

AristoleAristole (Greek Philosopher) (Greek Philosopher)

* About 300 BC* About 300 BC

* Classified based on method of reproduction* Classified based on method of reproduction

* Used the words like “genera” and “species”* Used the words like “genera” and “species”

* Grouped animals between those with blood and * Grouped animals between those with blood and

those without bloodthose without blood

* He had many errors in his classification system, but it * He had many errors in his classification system, but it

was used until the 1700swas used until the 1700s

Carolus LinnaeusCarolus Linnaeus

(1707 – 1778)(1707 – 1778)

Created the system of naming we use today.Created the system of naming we use today.

In taxonomy, a group or level of In taxonomy, a group or level of organization is called a taxonomic category organization is called a taxonomic category or or taxontaxon..

Binomial NomenclatureBinomial Nomenclature ““Bi” means 2Bi” means 2

““nomial” means namingnomial” means naming

Nomenclature means “the system of”Nomenclature means “the system of”

DefinedDefined::

In In Binomial NomenclatureBinomial Nomenclature, each , each species is assigned a species is assigned a two-parttwo-part

scientific name. (genus & species)scientific name. (genus & species)

Example of Binomial NomenclatureExample of Binomial NomenclaturePolar Bear is Polar Bear is Ursus maritimusUrsus maritimus

UrsusUrsus: genus : genus

Ursus contains 5 other kinds of bearsUrsus contains 5 other kinds of bears

maritimusmaritimus: species : species

The Latin word, The Latin word, maritimusmaritimus, refers to the sea., refers to the sea.

Polar bears often live on pack ice that floats in the sea. Polar bears often live on pack ice that floats in the sea.

Here We Go…Here We Go…Polar BearPolar Bear

Species: Species: maritimusmaritimusGenus: Genus: UrsusUrsus

Family: UrsidaeFamily: UrsidaeOrder: CarnivoraOrder: CarnivoraClass: MammaliaClass: MammaliaPhylum: ChordataPhylum: ChordataKingdom: AnimiliaKingdom: Animilia

What do these mean?...lets seeWhat do these mean?...lets see

*Do NOT have to write*

What they meanWhat they mean

Species: Species: maritimus maritimus (lives in marine environment)(lives in marine environment)

Genus: Genus: Ursus Ursus (kind of bear)(kind of bear)

Family: Ursidae (larger category of bears)Family: Ursidae (larger category of bears)

Order: Carnivora (meat-eating animals)Order: Carnivora (meat-eating animals)

Class: Mammalia (warm-blooded, hair, & milk)Class: Mammalia (warm-blooded, hair, & milk)

Phylum: Chordata (vertebrates)Phylum: Chordata (vertebrates)

Kingdom: Animilia (there are 6 kingdoms)Kingdom: Animilia (there are 6 kingdoms)

*Do NOT have to write*

How to remember:How to remember:Daa KKing ing PPhillip hillip CCame ame OOver ver FFor or GGreen reen SSaladalad

DDomain omain

KKingdom ingdom

PPhylum hylum

CClass lass

OOrder rder

FFamily amily

GGenus enus

SSpeciespecies

Phylum

Chordata

Class

Mammalia

Order

Carnivora

Family

Ursidae

Genus Ursus

Speciesmaritimus

Rules of the GameRules of the GameUniquenessUniqueness: Every name has to be unique. : Every name has to be unique.

Universality: Universality: Zoologists have adopted, by International Code of Zoologists have adopted, by International Code of Zoological Nomenclature, a set of rules for naming animals. A Zoological Nomenclature, a set of rules for naming animals. A single languagesingle language is to be used on a worldwide basis. All animals is to be used on a worldwide basis. All animals are given a generic name (common name) and specific name in are given a generic name (common name) and specific name in Latin &/or Greek (scientific name). Latin &/or Greek (scientific name).

These names are in These names are in italicsitalics when TYPED when TYPED or are or are underlinedunderlined when HAND WRITTEN. when HAND WRITTEN.

HumanHuman: Homo sapiens: Homo sapiensLion: Lion: Panthera leoPanthera leo

Taxonomy Video Taxonomy Video

If these three species belong to the same If these three species belong to the same genus, they are descended from a common genus, they are descended from a common ancestor.ancestor.

Genus species

Felis

domestica

negripes

margarita Sand cat`

Black Footed Cat

Domestic Cat

Felis domestica

Felis negripes

Felis margarita

A Problem with Traditional ClassificationA Problem with Traditional Classification Traditional classification systems relied on body structure comparisons Traditional classification systems relied on body structure comparisons

only (not DNA)only (not DNA)

Due to Due to convergent evolutionconvergent evolution, organisms that are quite different from each , organisms that are quite different from each

other evolve similar body structures.other evolve similar body structures.

Convergent EvolutionConvergent Evolution: Process by which unrelated : Process by which unrelated organisms independently evolve similarities when adapting to organisms independently evolve similarities when adapting to similar environments.similar environments.

Flying Squirrel…

Live in the US (GA)

Sugar Glider…

Live in Australia

Look similar, but totally unrelated!

Another Problem with Traditional ClassificationAnother Problem with Traditional Classification

Example: The Crab, The barnacle, & The limpetExample: The Crab, The barnacle, & The limpet

• The barnacle and the limpet have similarly The barnacle and the limpet have similarly shaped shells & look alikeshaped shells & look alike

• The crab has a very different body formThe crab has a very different body form

• Based on Based on anatomyanatomy, the barnacle & limpet could , the barnacle & limpet could be classified together and the crab in a different be classified together and the crab in a different group.group.

Related

This incorrect because crabs and barnacles are actually related

Modern Principles of ClassificationModern Principles of Classification

Modern classification system has its roots in the Modern classification system has its roots in the

system of Linnaeussystem of Linnaeus

Modern classification has been revised to reflect Modern classification has been revised to reflect

Darwinian PrincipleDarwinian Principle of common descent of common descent

Most recently, molecular systematics (DNA) has Most recently, molecular systematics (DNA) has driven the most recent revisions in classificationdriven the most recent revisions in classification

Crustaceans

Even though they do not look a like, crabs & barnacles are actually

related

Gastropods

Molted Exoskeleton

Segmentation

Free swimming Larva

Evolutionary Classification/SystematicsEvolutionary Classification/Systematics Biologists now group organisms into categories that Biologists now group organisms into categories that

represent lines of evolutionary descent, not just represent lines of evolutionary descent, not just physical similaritiesphysical similarities

Evolution Classification (Systematics)Evolution Classification (Systematics): Is : Is the strategy of grouping organisms together based on the strategy of grouping organisms together based on their evolutionary history.their evolutionary history.

Animal SystematicsAnimal SystematicsPhylogenyPhylogeny: Phylogenetic tree (: Phylogenetic tree (also known as also known as

evolutionary tree). Based on the study of evolutionary tree). Based on the study of characters that vary among species.characters that vary among species.

CharacterCharacter: : anything that has a genetic basis and anything that has a genetic basis and can be measured.can be measured.

Systematics First Used ONLY Morphology

Morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features.

Classification Using Classification Using CladogramsCladograms

CladogramCladogram: : A diagram that shows the A diagram that shows the evolutionary relationships among a group of organisms.evolutionary relationships among a group of organisms.

Crustaceans

Using Cladograms, you can see that crabs and barnacles share similar characteristics

because they both molt & are segmented

Gastropods

Molted Exoskeleton

Segmentation

Free swimming Larva

Crustaceans

You can also see that ALL have a free

swimming larva stage

Gastropods

Molted Exoskeleton

Segmentation

Free swimming Larva

The Three-Domain SystemThe Three-Domain System In 1990, a new taxonomic level called In 1990, a new taxonomic level called DomainDomain was was

introduced and changed how bacteria were introduced and changed how bacteria were classified.classified.

Domain ArchaeaDomain Archaea Domain BacteriaDomain Bacteria Domain Eukarya Domain Eukarya

There are 6 Kingdoms total: There are 6 Kingdoms total:

1. Eubacteria 2. Archaebacteria 1. Eubacteria 2. Archaebacteria

3. Protista 4. Fungi 5. Plantae 6. Animalia3. Protista 4. Fungi 5. Plantae 6. Animalia

Both are Bacteria

Everything else (Except viruses)

6 Kingdoms6 KingdomsEubacteria Archaebacteria Protista Fungi Plantae AnimaliaEubacteria Archaebacteria Protista Fungi Plantae Animalia

E. ecoli Paramecium Fern frodH. coccinea Homo sapiensPyrococcus furiosus

ProkaryoteProkaryote Eukaryote Eukaryote Eukaryote Eukaryote

Autotroph or

heterotroph

Autotroph orheterotroph

Autotroph/heterotroph

Heterotroph HeterotrophAutotroph

Most common bacteria

Live in very hot places

Includes Algae

Don’t belong in other euk

Cell walls &

Chloroplasts

Release enzymes to digest

food

No cell wall

No chloroplasts

Multicellular

“Ancient Bacteria”

Systematics Systematics FirstFirst Used Morpholog Used Morphology…y…

Now also use other methods too!Now also use other methods too!

• Molecular EvidenceMolecular Evidence - - is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism's evolutionary relationships.

Systematics Systematics FirstFirst Used Morpholog Used Morphology…y…Now use other methods too!Now use other methods too!

• Biochemical Evidence – is the analysis of similar chemical makeups of organisms to compare evolutionary relationships.

Systematics Systematics FirstFirst Used Morpholog Used Morphology…y…Now use other methods too!Now use other methods too!

Click Click HERE HERE for videofor video

• Embryonic Evidence – is the analysis of the early development of embryos an comparing them to other animals.

Other Patterns of OrganizationOther Patterns of Organization Unicellular Level of OrganizationUnicellular Level of Organization

Protista- one-celled organismsProtista- one-celled organisms

Diploblastic OrganizationBody parts organized into layers derived from two tissue Body parts organized into layers derived from two tissue

layerslayers1.1. Ectoderm – gives rise to epidermis (outer layer)Ectoderm – gives rise to epidermis (outer layer)

2.2. Endoderm – gives rise to gastrodermis , the tissue that lines Endoderm – gives rise to gastrodermis , the tissue that lines the gut cavitythe gut cavity

Examples: Jellyfish & HydraExamples: Jellyfish & Hydra

Amoeba

Hydra

Other Patterns of OrganizationOther Patterns of OrganizationTriploblastic AnimalsTriploblastic Animals

Tissues derived from three embryonic layersTissues derived from three embryonic layers1.1. EctodermEctoderm

2.2. Mesoderm – found in middle. Gives rise to Mesoderm – found in middle. Gives rise to supportive, contractile, and blood cells.supportive, contractile, and blood cells.

3.3. EndodermEndoderm

Other Patterns of OrganizationOther Patterns of OrganizationTriploblastic AnimalsTriploblastic Animals (continued) (continued)

Organized based on the presence or absence of Organized based on the presence or absence of body cavitybody cavity

Body Cavity Body Cavity – fluid-filled space in which internal organs – fluid-filled space in which internal organs can be suspended and separated from body wall.can be suspended and separated from body wall.

A true body cavity is known as a A true body cavity is known as a coelomcoelom..

Advantages of a Body CavityAdvantages of a Body Cavity

1.1. Provide more room for organ developmentProvide more room for organ development

2.2. Provide more surface area for diffusion of gases, Provide more surface area for diffusion of gases, nutrients, & wastes into & out of organsnutrients, & wastes into & out of organs

3.3. Provide an area for storageProvide an area for storage

4.4. Often act as hydrostatic skeletons (as in earthworm)Often act as hydrostatic skeletons (as in earthworm)

5.5. Provide a vehicle for eliminating wastes & Provide a vehicle for eliminating wastes & reproductive products from the bodyreproductive products from the body

6.6. Facilitate increased body sizeFacilitate increased body size

More Symmetry Terms to KnowMore Symmetry Terms to KnowWrite these down on paper!Write these down on paper!

(not in notes)(not in notes) InferiorInferior – – BelowBelow a point of reference a point of reference

SuperiorSuperior – – AboveAbove a point of reference a point of reference

TerminalTerminal – – MiddleMiddle or center point of reference or center point of reference

Phyla To KnowPhyla To KnowPorifera: SpongesPorifera: Sponges

Cnidaria: Jellyfish, Sea Anemones, CoralsCnidaria: Jellyfish, Sea Anemones, Corals

Echinodermata: Sea Urchin, Starfish, Sand DollarsEchinodermata: Sea Urchin, Starfish, Sand Dollars

Mollusca: Snails, Clams, OctopusMollusca: Snails, Clams, Octopus

Arthropoda: Insects, Crustaceans, SpidersArthropoda: Insects, Crustaceans, Spiders

Chordata: VertebratesChordata: Vertebrates

The End.