Organizing Life’s Organizing Life’s DiversityDiversityChapter 17Chapter 17

EVERYONE classifies…EVERYONE classifies…

Doesn’t have to be just for living Doesn’t have to be just for living thingsthings

In your house, where would I find:In your house, where would I find:cerealcerealdrinking glassesdrinking glassessockssocksblue jeansblue jeansbath towelsbath towelsextra bars of soapextra bars of soap

ClassificationClassification Classify Classify – to group things together based on – to group things together based on

similaritiessimilarities Why ClassifyWhy Classify??

To make organisms/items easier to identifyTo make organisms/items easier to identify To make organisms/items easier to compareTo make organisms/items easier to compare

How do we classifyHow do we classify?? CompareCompare Traits Traits – features or characteristics of – features or characteristics of

an organism/iteman organism/item• When dealing with living things, the science of When dealing with living things, the science of

Classification is called Classification is called TaxonomyTaxonomy

2 Big Challenges of 2 Big Challenges of ClassificationClassification

1. 1. Many different kinds of living things -- Many different kinds of living things -- diversitydiversity

Today we have identified and named 1.5 Today we have identified and named 1.5 million species million species

Millions more are believed to be unclassifiedMillions more are believed to be unclassified Organisms scattered all over the world, some Organisms scattered all over the world, some

in harsh, difficult to reach environments in harsh, difficult to reach environments 2. 2. Classifications are made by peopleClassifications are made by people

Opinions may differ from scientist to scientistOpinions may differ from scientist to scientist

Timeline of ClassificationTimeline of Classification1. 384 – 322 B.C. Aristotle1. 384 – 322 B.C. Aristotle

2 Kingdom Broad Classification2 Kingdom Broad Classification2. 1735 - Carl Linnaeus 2. 1735 - Carl Linnaeus

2 Kingdom Multi-divisional Classification2 Kingdom Multi-divisional Classification(Kingdom, Phylum, Class, Order, Family Genus, (Kingdom, Phylum, Class, Order, Family Genus,

Species)Species)3. 3. Evolutionary ClassificationEvolutionary Classification – (After Darwin) – (After Darwin)

Group By lines of Evolutionary DescentGroup By lines of Evolutionary Descent4. 4. 5 Kingdom System5 Kingdom System – 1950s – 1950s5. 5. 6 Kingdom System6 Kingdom System – early 1990s – early 1990s6. 6. 3 Domain System3 Domain System – late 1990s – late 1990s

Early Classification – Aristotle Early Classification – Aristotle 384-322 B.C.384-322 B.C.

PlantPlantAnimalAnimal

GreenGreen Not greenNot green

Does not moveDoes not move Does moveDoes move

Tree Shrub

Herb Air Land Water

•Size

•Pattern of growth

•Where live

How would you classify How would you classify these using the these using the

Plant/Animal system?Plant/Animal system?

Aristotle’s Grouping of life not specific enough

Carl LinnaeusCarl Linnaeus

Linnaeus (1735) Swedish BotanistLinnaeus (1735) Swedish Botanist Reworked Classification systemReworked Classification system

*Based on Body structure -- morphology*Based on Body structure -- morphology Called his classification Called his classification Systema NaturaeSystema Naturae Used a hierarchy of categories to classifyUsed a hierarchy of categories to classify

*Compared physical traits of Organisms*Compared physical traits of Organisms*Used Comparative Morphology *Used Comparative Morphology

Linnaeus Divisions Still Linnaeus Divisions Still Used in Modern Used in Modern ClassificationClassification

1. 1. Kingdom – largest groupKingdom – largest group2. Phylum2. Phylum

3. Class3. Class4. Order4. Order

5. Family5. Family6. Genus6. Genus 7. Species 7. Species (Most Closely (Most Closely

Related)Related)

Mnemonic Device – To help Mnemonic Device – To help remember categories and remember categories and

orderorder Kingdom - Kingdom - KKinging

Phylum - Phylum - PPhilliphillip

Class – Class – CCame ame

Order – Order – OOver ver

Family - Family - FForor

Genus - Genus - GGingeringer

Species - Species - SSnapsnaps

TaxonsTaxons

Within each category, a particular group is Within each category, a particular group is called a called a TaxonTaxon

Many Taxons for each categoryMany Taxons for each category Ex: Ex:

MammaliaMammalia is the Taxon for the is the Taxon for the ClassClass category in Humanscategory in Humans

CarnivoraCarnivora is the Taxon for the Order is the Taxon for the Order category in Lionscategory in Lions

Similarities/Changes Similarities/Changes Linnaeus Made to Linnaeus Made to Aristotle’s SystemAristotle’s System*Both had 2 “Kingdom” Systems*Both had 2 “Kingdom” Systems

PlantaePlantae and and AnimaliaAnimalia

Differences:Differences:1. Plants and Animals were 1. Plants and Animals were classified using more classified using more

divisionsdivisions - to account for diversity - to account for diversity2. 2. Each divisionEach division from Kingdom to species is from Kingdom to species is based on based on

specific traitsspecific traits Ex: Vertebrae, Mammary Glands, DietEx: Vertebrae, Mammary Glands, Diet

3. 3. TaxonsTaxons of each group are of each group are descriptive of traitdescriptive of trait being being used in forming that groupused in forming that group Ex: Class Ex: Class MammaliaMammalia – – mammary glandsmammary glands are used to nurse are used to nurse

young young

Linnaeus Introduced Scientific Linnaeus Introduced Scientific NamingNaming Binomial NomenclatureBinomial Nomenclature is the 2 word is the 2 word scientific namescientific name of of

an organisman organismUsesUses GenusGenus and and SpeciesSpecies

GGenus is capitalized, not enus is capitalized, not sspecies, all pecies, all italicizeditalicized In In writingwriting the name, can’t italicize, so the name, can’t italicize, so underlineunderline Used Used LatinLatin – Universal unifying, – Universal unifying, ““deaddead”” language language

*Latin can be *Latin can be understood by all scientistsunderstood by all scientists, regardless of , regardless of native languagenative language

*Uniform, unlike common name usage*Uniform, unlike common name usage Ex: Ex: Cougar, Puma, Panther-Cougar, Puma, Panther- all all same organismsame organism name depends upon where you live, but name depends upon where you live, but Scientific name is the Scientific name is the

same WORLDWIDEsame WORLDWIDE FelisFelis concolorconcolor

Example ClassificationExample Classification LionLion 1. 1. Kingdom – AnimaliaKingdom – Animalia ( (all Animalsall Animals))

2.2. PhylumPhylum – – ChordataChordata (All vertebrate animals) (All vertebrate animals)3. 3. Class – MammaliaClass – Mammalia (All Mammals – (All Mammals –

mammary glands)mammary glands)

4. 4. Order – CarnivoraOrder – Carnivora (Meat eaters) (Meat eaters)

5. 5. Family – FelidaeFamily – Felidae (includes all Cats) (includes all Cats)

6. 6. Genus – Genus – PantheraPanthera (Includes all (Includes all roaring Cats)roaring Cats)

7. 7. Species – Species – leoleo ( (LionsLions))

From Kingdom to From Kingdom to SpeciesSpecies

Classification KeyClassification Key Also Known as: Also Known as:

Dichotomous Key, Biological KeyDichotomous Key, Biological Key Useful in Identifying Organisms Useful in Identifying Organisms

Based on Based on Comparison of Comparison of Morphological TraitsMorphological Traits Use Use physical featuresphysical features to compare, contrast to compare, contrast Determine if Organism is in groupDetermine if Organism is in group or not, based on Key criteria or not, based on Key criteria

At each level you only have a At each level you only have a few contrasting characteristics to few contrasting characteristics to choose fromchoose from (if have, if not have) (if have, if not have) Ex: Tennis shoe, non Tennis shoeEx: Tennis shoe, non Tennis shoe Body shape plans, Characteristics such as furBody shape plans, Characteristics such as fur

Refer to your Shark lab handoutRefer to your Shark lab handout

Tools Used to Classify Tools Used to Classify OrganismsOrganisms

Comparative Morphology (structural Comparative Morphology (structural similarities)similarities)

Breeding behavior (behavioral similarities)Breeding behavior (behavioral similarities) Geographical distribution (biogeography)Geographical distribution (biogeography) Chromosome comparisons Chromosome comparisons BiochemistryBiochemistry Evolutionary RelationshipsEvolutionary Relationships

Comparative MorphologyComparative Morphology Body structureBody structure Presence/absence of body partsPresence/absence of body parts

Ex. Number of limbsEx. Number of limbsEx. Presence of feathersEx. Presence of feathersEx. Presence of flowersEx. Presence of flowers

*REMEMBER THOUGH--*REMEMBER THOUGH--This can be misleading – divergent and This can be misleading – divergent and

convergent evolution could play a part convergent evolution could play a part and appearance is NOT indictitive of and appearance is NOT indictitive of true taxonomic relationships…..true taxonomic relationships…..

Breeding BehaviorBreeding Behavior

Differs between speciesDiffers between species

Ex. Mating calls of frogsEx. Mating calls of frogs

Differences in breeding behavior Differences in breeding behavior allows for SPECIATION to occur, allows for SPECIATION to occur, and can result in and can result in isolationisolation

BiogeographyBiogeography

Finches, tortoises in GalapagosFinches, tortoises in Galapagos Bears on different continentsBears on different continents Sugar glider and flying squirrelSugar glider and flying squirrel

Chromosome comparisons Chromosome comparisons and Biochemistryand Biochemistry

Number and structure of Number and structure of chromosomes are set from species to chromosomes are set from species to species!!!species!!!

Similarities in chromosomes and the Similarities in chromosomes and the proteins that are made leads to idea proteins that are made leads to idea that orgs are related.that orgs are related.

Ex. Cauliflower, cabbage, kale, Ex. Cauliflower, cabbage, kale, broccolibroccoli

Molecular clocksMolecular clocksPage 530

Two types of data for Two types of data for molecular clocks…molecular clocks…

Mitochondrial DNA –Mitochondrial DNA –

Ribosomal RNA – Ribosomal RNA –

Evolutionary Relationships Evolutionary Relationships ––

Cladistics vs. SystematicsCladistics vs. SystematicsBoth are Phylogenetic Classification Both are Phylogenetic Classification

models – deal with evolutionary historymodels – deal with evolutionary history

DifferenceDifference*Cladistics uses a “order of appearance” *Cladistics uses a “order of appearance”

approach – cladogramapproach – cladogramthis shows groups of organisms this shows groups of organisms evolving from a common ancestor and evolving from a common ancestor and utilizes “derived characters”, but not utilizes “derived characters”, but not specific timesspecific times

In cladistics, In cladistics, similar characteristics that come from a similar characteristics that come from a common ancestorcommon ancestor are used to divide organisms into groups. are used to divide organisms into groups.

A cladogram will begin by grouping organisms based on a A cladogram will begin by grouping organisms based on a characteristic displayed by all the members of the group. characteristic displayed by all the members of the group.

Subsequently, the larger group, or Subsequently, the larger group, or cladeclade, will contain , will contain increasingly smaller groups (clades) that share the traits of increasingly smaller groups (clades) that share the traits of the clades before them, but also exhibit distinct changes as the clades before them, but also exhibit distinct changes as the organism evolves.the organism evolves.

To make a To make a cladogram,cladogram, scientists first collect data on the scientists first collect data on the features of all the organisms they hope to classify.features of all the organisms they hope to classify.

This data is then analyzed to determine which characteristics This data is then analyzed to determine which characteristics were present in what could have been a common ancestor were present in what could have been a common ancestor and which might have been developed inand which might have been developed in

later times.later times.

Page 525

Cladogram vs. Comparative Cladogram vs. Comparative (Traditional) (Traditional) Morphology p.452Morphology p.452

Derived Characters

Common Ancestor

Common Ancestor

Common Ancestor

<-- Common Ancestor

SystematicsSystematics uses a fan-like approach uses a fan-like approach that communicates a timelinethat communicates a timeline

Instead of a few derived characters, Instead of a few derived characters, systematics uses as many systematics uses as many characteristics of orgs as possible characteristics of orgs as possible and makes and makes groupingsgroupings based on based on overall degree of similarityoverall degree of similarity

Timeline of ClassificationTimeline of Classification1. 384 – 322 B.C. Aristotle1. 384 – 322 B.C. Aristotle

2 Kingdom Broad Classification2 Kingdom Broad Classification2. 1735 - Carl Linnaeus 2. 1735 - Carl Linnaeus

2 Kingdom Multi-divisional Classification2 Kingdom Multi-divisional Classification(Kingdom, Phylum, Class, Order, Family Genus, (Kingdom, Phylum, Class, Order, Family Genus,

Species)Species)3. 3. Evolutionary ClassificationEvolutionary Classification – (After Darwin) – (After Darwin)

Group By lines of Evolutionary DescentGroup By lines of Evolutionary Descent4. 4. 5 Kingdom System5 Kingdom System – 1950s – 1950s5. 5. 6 Kingdom System6 Kingdom System – early 1990s – early 1990s6. 6. 3 Domain System3 Domain System – late 1990s – late 1990s

From 2 Kingdoms to 6From 2 Kingdoms to 6p. 458p. 458

6 Kingdom System moves to 6 Kingdom System moves to

3 Domains3 Domains

Animalia

Plantae

Fungi

Protista

Eubacteria

Archaeabacteria

4. Three Domain System4. Three Domain System

11. . Domain BacteriaDomain Bacteria Corresponds to Corresponds to Eubacteria KingdomEubacteria Kingdom Unicellular ProkaryoticUnicellular Prokaryotic OrganismsOrganisms

No Nucleus No Nucleus Ecologically Diverse – live everywhere!Ecologically Diverse – live everywhere! Metabolically DiverseMetabolically Diverse

Cell Walls contain substance called Cell Walls contain substance called Peptidoglycan Peptidoglycan – – special protein and sugarspecial protein and sugar

Trait used to distinguish between Bacteria Trait used to distinguish between Bacteria and Archaeaand Archaea

Target of many antibioticsTarget of many antibiotics

Three Domain SystemThree Domain System 22. . Domain ArchaeaDomain Archaea – “ – “Ancient BacteriaAncient Bacteria””

Corresponds to Corresponds to Kingdom ArchaebacteriaKingdom Archaebacteria Unicellular, ProkaryotesUnicellular, Prokaryotes

Metabolically DiverseMetabolically Diverse No nucleusNo nucleus Live in Live in Extreme environmentsExtreme environments like those of like those of

early Earthearly Earth Cell walls Cell walls without Peptidoglycanwithout Peptidoglycan

a trait used to distinguish between Archaea and Bacteria domains

Three Domain SystemThree Domain System

3. 3. EukaryaEukarya Contains Contains Kingdoms: Kingdoms:

Protista, Fungi, Plantae, AnimaliaProtista, Fungi, Plantae, Animalia Eukaryotic, single Eukaryotic, single oror multi-cellular multi-cellular

OrganismsOrganismsNucleusNucleusMost visible lifeMost visible lifeHumans are in Domain EukaryaHumans are in Domain Eukarya