1 Classificat Classificat ion ion Chapter 17 Chapter 17 copyright cmassengale
1
ClassificatioClassificationn
Chapter 17 Chapter 17
copyright cmassengale
2
•There are There are 13 billion13 billion known known species of organismsspecies of organisms
•This is This is only 5% of allonly 5% of all organisms that ever organisms that ever lived!!!!!lived!!!!!
•New organismsNew organisms are still are still being found and identifiedbeing found and identified
Species of OrganismsSpecies of Organisms
copyright cmassengale
3
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
copyright cmassengale
4
Benefits of ClassifyingBenefits of Classifying
•Accurately & uniformlyAccurately & uniformly names organisms names organisms
•Prevents Prevents misnomersmisnomers such such as starfish & jellyfish that as starfish & jellyfish that aren't really fish aren't 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”??”??
copyright cmassengale
5
Confusion in Using Different Confusion in Using Different Languages for NamesLanguages for Names
copyright cmassengale
6
Latin Names are Understood Latin Names are Understood by all Taxonomistsby all Taxonomists
copyright cmassengale
7
Early TaxonomistsEarly Taxonomists
•2000 years ago, 2000 years ago, AristotleAristotle was the was the first taxonomistfirst taxonomist
•Aristotle divided Aristotle divided organisms into organisms into plants & animalsplants & animals
•He He subdividedsubdivided them by their them by their habitathabitat ---land, sea, ---land, sea, or air dwellers or air dwellers
copyright cmassengale
8
Early TaxonomistsEarly Taxonomists•John Ray, a John Ray, a
botanist,botanist, was was the first to use the first to use Latin for Latin for namingnaming
•His His namesnames were were very longvery long descriptions descriptions telling telling everything everything about the plantabout the plant
copyright cmassengale
9
Carolus LinnaeusCarolus Linnaeus1707 – 17781707 – 1778
•18th century taxonomist
•Classified organisms by their structure
•Developed naming system still used today
copyright cmassengale
10
Carolus LinnaeusCarolus Linnaeus
•Called the Called the “Father of “Father of Taxonomy”Taxonomy”
•Developed the modern Developed the modern system of naming system of naming known as known as binomial binomial nomenclaturenomenclature
•Two-wordTwo-word name (Genus name (Genus & species)& species)
copyright cmassengale
11
Standardized Standardized NamingNaming
•Binomial Binomial nomenclature nomenclature usedused
•Genus speciesGenus species
•Latin or GreekLatin or Greek
•ItalicizedItalicized in print in print
•Capitalize genusCapitalize genus, , but NOT speciesbut NOT species
•UnderlineUnderline when when writingwriting
Turdus Turdus migratoriusmigratorius
American American RobinRobincopyright cmassengale
12
Binomial NomenclatureBinomial Nomenclature
Which TWO are more closely related?copyright cmassengale
13
Rules for Naming OrganismsRules for Naming Organisms
•The The International Code for International Code for Binomial Nomenclature Binomial Nomenclature contains the rules for contains the rules for naming organismsnaming organisms
•All names must be approved All names must be approved by by International Naming International Naming CongressesCongresses (International (International Zoological Congress)Zoological Congress)
•This This prevents duplicatedprevents duplicated namesnames
copyright cmassengale
14
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
copyright cmassengale
15
Hierarchy-Taxonomic Hierarchy-Taxonomic GroupsGroups
DomainKingdom
Phylum (Division – used for plants)
Class Order Family
Genus Species
BROADEST BROADEST TAXONTAXON
Most Specific
copyright cmassengale
16
DDumbumb
KKinging
PPhilliphillip
CCameame
OOverver
FForor
GGooseberrooseberryy
SSoup!oup!copyright cmassengale
17copyright cmassengale
18
•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
copyright cmassengale
19
ARCHAEA
•Probably the 1st cells to evolve
•Live in HARSH environments
•Found in:
–Sewage Treatment Plants
–Thermal or Volcanic Vents
–Hot Springs or Geysers that are acid
–Very salty water (Dead Sea; Great Salt Lake)
copyright cmassengale
20
ARCHAEAN
copyright cmassengale
21
BACTERIA
•Some may cause DISEASE
•Found in ALL HABITATS except harsh ones
•Important decomposers for environment
•Commercially important in making cottage cheese, yogurt, buttermilk, etc.
copyright cmassengale
22
Live in the intestines of animalsLive in the intestines of animals
copyright cmassengale
23
Domain Eukarya is Domain Eukarya is Divided into KingdomsDivided into Kingdoms•EubacteriaEubacteria (true-bacteria) (true-bacteria)
•ArchaebacteriaArchaebacteria ( ancient bacteria) ( ancient bacteria)
•ProtistaProtista ( not plants animals or ( not plants animals or fungi) fungi)
•FungiFungi (mushrooms, yeasts …) (mushrooms, yeasts …)
•PlantaePlantae (multicellular plants) (multicellular plants)
•AnimaliaAnimalia (multicellular animals) (multicellular animals)
copyright cmassengale
EUBACTERIA•Occur in many shapes ( Bacilli, Spirilla, and
Cocci)
• cells walls made of peptidoglycan- a protein carbohydrate.
•Live in a wide variety of environments
•Can cause many diseases
copyright cmassengale 24
Archaebacteria•Cell walls do not have peptidoglycan
•- live in harsh environmnets
•“Archae” means ancient
•Three groups of Archaebaqcter ia exist:1.Methanogens: convert hydrogen gas and
carbon dioxide into methane gas. (oxygen is poisonous to them) live in anaerobic environments such as marine mud and sewage, cow intestines.
2.Halophiles: “salt loving” archaea. Environmnets like the great salt lake and the dead sea.
3.Thermoacidophiles: live in very acidic environments that have very high temperatures. Ex. Hot springs and hydrothermal vents.
copyright cmassengale 25
27
ProtistaProtista•Most are unicellularMost are unicellular
•Some are Some are multicellularmulticellular
•Some are Some are autotrophicautotrophic, while , while others are others are heterotrophicheterotrophic
•AquaticAquatic
•Common examples Common examples are amoeba and are amoeba and paramecium, sea paramecium, sea weeds and moldsweeds and molds
copyright cmassengale
28
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
copyright cmassengale
29
PlantaePlantae
•MulticellularMulticellular
•AutotrophicAutotrophic
•Absorb Absorb sunlight sunlight to make glucose to make glucose – Photosynthesis– Photosynthesis
•Cell walls made Cell walls made of of cellulosecellulose
copyright cmassengale
30
AnimaliaAnimalia
•MulticellularMulticellular
•Ingestive Ingestive heterotrophsheterotrophs (consume (consume food & digest food & digest it inside their it inside their bodies)bodies)
•Feed on Feed on plantsplants or or animalsanimals
copyright cmassengale
31copyright cmassengale
32
TaxonsTaxons
•Most Most generagenera contain a contain a number of similar number of similar speciesspecies
•The genus The genus HomoHomo is an is an exception (only contains exception (only contains modern humans)modern humans)
•Classification is based on evolutionary evolutionary relationshipsrelationships
copyright cmassengale
33
Basis for Modern Basis for Modern TaxonomyTaxonomy
•Phylogenetics- analysis of the evolutionary or ancestral relationships among taxa
•Homologous structuresHomologous structures (same (same structure, different function)structure, different function)
•Similar Similar embryoembryo developmentdevelopment
•Molecular SimilarityMolecular Similarity in in DNADNA, , RNARNA, or , or amino acidamino acid sequence sequence of Proteinsof Proteins
copyright cmassengale
34
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
copyright cmassengale
35
Primate Primate CladogramCladogram
copyright cmassengale
36
Dichotomous KeyingDichotomous Keying
•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
copyright cmassengale
37
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
copyright cmassengale
copyright cmassengale 38