Classification & Diversity Chapter 18 Biology 112

Classification & DiversityClassification & Diversity

Chapter 18Chapter 18

Biology 112Biology 112

Importance of ClassificationImportance of Classification To study the vast number of living and fossil To study the vast number of living and fossil

organisms (est. up to 40 million different species)organisms (est. up to 40 million different species) Provide natural groupings of living thingsProvide natural groupings of living things TaxonomyTaxonomy – the study of naming organisms – the study of naming organisms Problems with “common” names ex: June Bug refers Problems with “common” names ex: June Bug refers

to over a dozen different beetlesto over a dozen different beetles Early scholars tried to standardize the system by Early scholars tried to standardize the system by

giving organisms a Latin name, “the universal giving organisms a Latin name, “the universal language of science”language of science”

Problem with Latin names – difficult to use, changed Problem with Latin names – difficult to use, changed regularly, and some had 15 namesregularly, and some had 15 names

Latin NamesLatin Names

One carnation like flower had the name:One carnation like flower had the name:

““Dianthus floribus solitariis squamis calycinis Dianthus floribus solitariis squamis calycinis subovatis brevissimus corollis crenatis”subovatis brevissimus corollis crenatis”

Biologists needed a single, stable concise way Biologists needed a single, stable concise way of naming thingsof naming things

Binomial NomenclatureBinomial Nomenclature

Swedish Botanist Swedish Botanist Carolus LinnaeusCarolus Linnaeus (1707- (1707-1787) devised a shorthand method of naming 1787) devised a shorthand method of naming organisms called the organisms called the system of binomial system of binomial nomenclaturenomenclature

Used worldwide Used worldwide Gives each species a unique two part Latin Gives each species a unique two part Latin

name known as the scientific namename known as the scientific name Carnation type plant: Carnation type plant: Dianthus caryophyllusDianthus caryophyllus

Binomial Nomenclature – Scientific Binomial Nomenclature – Scientific NamingNaming

Examples: Examples: Homo sapiens, Castor canadensis, Acer rubrumHomo sapiens, Castor canadensis, Acer rubrum First word = First word = genusgenus and it’s first letter is always and it’s first letter is always

capitalizedcapitalized and word and word italicizeditalicizedGenusGenus is usually a proper noun or common name used is usually a proper noun or common name used

by the Romans; ex: similar cats were in the genus by the Romans; ex: similar cats were in the genus FelisFelis, dogs in the genus , dogs in the genus CanisCanis

Second word = Second word = speciesspecies Species is usually a Greek or Latin adjective that Species is usually a Greek or Latin adjective that

describes a describes a significant characteristicsignificant characteristic of the species of the species

Naming cont….Naming cont….

Example:Example:

Campanula rotundifoliaCampanula rotundifolia

(campana means “bell”; rotund means “round”; (campana means “bell”; rotund means “round”; folia means “leaves”folia means “leaves”

A bell flower with rounded leavesA bell flower with rounded leaves

Classifying in Classifying in BiologyBiology

Linneaus’s Classification System:Linneaus’s Classification System:

Human Cougar Tiger Pintail Duck

Kingdom Animalia Animalia Animalia Animalia

Phylum/Division

Chordata Chordata Chordata Chordata

Class Mammalia Mammalia Mammalia Aves

Order Primate Carnivora Carnivora Anseriformes

Family Homindae Felidae Felidae Anatidae

Genus Homo Felis Panthera Anas

Species sapiens concolor tigris acuta

Dichotomous KeysDichotomous Keys

Classification manuals to conduct Classification manuals to conduct identification workidentification work

Constructed so that a series of choices must be Constructed so that a series of choices must be mademade

If choices are made correctly, the taxonomist If choices are made correctly, the taxonomist is led to the name of the organism being is led to the name of the organism being identified.identified.

HWK Time!!HWK Time!!

112 Hwk: guided reading HWK 18-1 112 Hwk: guided reading HWK 18-1

More Classifying Using More Classifying Using Dichotomoous KeysDichotomoous Keys

3 Keys – Go in lab Duotang!!3 Keys – Go in lab Duotang!!

Classification Classification

Section 18.2 & 18.3Section 18.2 & 18.3

Phylogeny:Phylogeny:

Evolutionary relationships among organismsEvolutionary relationships among organisms Biologists group organisms into categories that Biologists group organisms into categories that

represent lines of represent lines of evolutionary descentevolutionary descent, not just , not just physical similarities.physical similarities.

The strategy of grouping organisms together based on The strategy of grouping organisms together based on their their evolutionary history is called evolutionary history is called evolutionary evolutionary classificationclassification

Evidence for Evolution – Evidence for Evolution – Homologous Structures?Homologous Structures?

Evidence for Evolution – Vestigial Evidence for Evolution – Vestigial Structures?Structures?

Evidence for Evolution – Embryonic Evidence for Evolution – Embryonic Development?Development?

Evidence for Evolution – Evidence for Evolution – Physiology/Biochemistry?Physiology/Biochemistry?

Linnaean System vs. Evolutionary System Linnaean System vs. Evolutionary System of Classificationof Classification

KPCOFGS came way before scientists KPCOFGS came way before scientists understood that organisms evolved.understood that organisms evolved.

The Phylogenic (Evolutionary) System names The Phylogenic (Evolutionary) System names only only cladesclades

CladesClades are groups of organisms that are all are groups of organisms that are all descended from a common ancestordescended from a common ancestor

CladogramCladogram

Tree of LifeTree of Life

Five Kingdoms of ClassificationFive Kingdoms of Classification

Linnaeus – 2 Kingdoms (Animals and PlantsLinnaeus – 2 Kingdoms (Animals and PlantsLED TO:LED TO: 1.1. ProtistaProtista2.2. FungiFungi3.3. MoneraMonera4.4. PlantaePlantae5.5. AnimaliaAnimalia

Recent Years:Recent Years:

Six Kingdoms:Six Kingdoms:1.1. EubacteriaEubacteria2.2. ArchaebacteriaArchaebacteria3.3. ProtistaProtista4.4. FungiFungi5.5. PlantaePlantae6.6. AnimaliaAnimalia

TODAY = 3 Domain SystemTODAY = 3 Domain System

DomainsDomains::

1.1. EukaryaEukarya (protists, fungi, plants, animals) (protists, fungi, plants, animals) (uni and multicellular/eukaryotic)(uni and multicellular/eukaryotic)

2.2. BacteriaBacteria (unicellular/prokaryotic)(unicellular/prokaryotic)

3.3. ArchaeArchae (unicellular/prokaryotic)(unicellular/prokaryotic)

So what is the difference between 2 &3?So what is the difference between 2 &3?

Guided Reading AssignmentGuided Reading Assignment

18-2/18-3 – HWk check on Thursday!!18-2/18-3 – HWk check on Thursday!!

Bio 111 AssignmentBio 111 Assignment

1.1. Read pages 451-461Read pages 451-461

2.2. Copy Page 459 on ONE FULL page for your Copy Page 459 on ONE FULL page for your notes***notes***

3.3. Answer questions 1-6 on page 461Answer questions 1-6 on page 461

4.4. Answer MC 1-10 on page 464Answer MC 1-10 on page 464

CLASSIFICATION REVIEWCLASSIFICATION REVIEW

BIOLOGY 112BIOLOGY 112

1. Why do Biologists assign each 1. Why do Biologists assign each organism a universally accepted organism a universally accepted

name?name?

To provide consistency and avoid confusionTo provide consistency and avoid confusion

What criteria are used to classify an What criteria are used to classify an organism?organism?

Evolutionary relationships as well as structural Evolutionary relationships as well as structural similarities of the organismsimilarities of the organism

What features of Binomial What features of Binomial Nomenclature make it useful for Nomenclature make it useful for

scientists?scientists? Each name is unique. Each scientific name Each name is unique. Each scientific name

(genus, species) is assigned to only 1 species, (genus, species) is assigned to only 1 species, so different species are not confusedso different species are not confused

Sequence Linnaeus’s seven Sequence Linnaeus’s seven taxonomic categories from smallest taxonomic categories from smallest

to largest:to largest:

Species, genus, family, order, class, phylum Species, genus, family, order, class, phylum and Kingdom and Kingdom

Explain the goal of evolutionary Explain the goal of evolutionary classification:classification:

Group organisms based on their evolutionary Group organisms based on their evolutionary history instead of grouping only according to history instead of grouping only according to physical similaritiesphysical similarities

How is a Cladogram used in How is a Cladogram used in classification?classification?

It is an attempt to trace the process of It is an attempt to trace the process of evolution in a group of organisms by focusing evolution in a group of organisms by focusing on unique shared derived features that appear on unique shared derived features that appear in some organisms but not othersin some organisms but not others

How Do Biologists use DNA and How Do Biologists use DNA and RNA to Classify Organisms?RNA to Classify Organisms?

They choose segments that are similar in all or They choose segments that are similar in all or many organisms and compare sequences many organisms and compare sequences within those molecules. The more similar within those molecules. The more similar between species, the closer the evolutionary between species, the closer the evolutionary relationships.relationships.

What is Phylogeny?What is Phylogeny?

Study of evolutionary relationships among Study of evolutionary relationships among organismsorganisms

Describe how a Molecular Clock is used to Estimate the Describe how a Molecular Clock is used to Estimate the Length of Tie that Two Related Species Have Been Evolving Length of Tie that Two Related Species Have Been Evolving

Independently:Independently:

Relies on a repeating process or MUTATION, Relies on a repeating process or MUTATION, and a comparison of DNA sequences in two and a comparison of DNA sequences in two species to see how alike or dissimilar the genes species to see how alike or dissimilar the genes are.are.

The degree of dissimilarity is, in turn, an The degree of dissimilarity is, in turn, an indication of how long ago the species shared indication of how long ago the species shared a common ancestora common ancestor

How do Domains and Kingdoms How do Domains and Kingdoms Differ?Differ?

A domain is more inclusive and larger than a A domain is more inclusive and larger than a kingdomkingdom

What characteristics are used to What characteristics are used to place an organism in the domain place an organism in the domain

Bacteria?Bacteria? Unicellular and ProkaryoticUnicellular and Prokaryotic Cell walls contain peptidoglycanCell walls contain peptidoglycan

Which domain consists of Which domain consists of prokaryotes whose cell walls lack prokaryotes whose cell walls lack

peptidoglycan?peptidoglycan?

Kingdom ArchaeaKingdom Archaea

Describe the 4 Kingdoms that Describe the 4 Kingdoms that comprise the Domain Eukarya:comprise the Domain Eukarya:

Protists, Fungi, Plantae, AnimaliaProtists, Fungi, Plantae, Animalia

What characteristic(s) differentiate the What characteristic(s) differentiate the kingdom Animalia from Plantae?kingdom Animalia from Plantae?

Unlike members of the Plantae kingdom, Unlike members of the Plantae kingdom, members of the Animalia kingdom are members of the Animalia kingdom are heterotrophic, do not have cell walls, and are heterotrophic, do not have cell walls, and are motile.motile.