classification

ClassificationClassification

•taxonomy

–science of grouping and naming organisms based on shared characteristics

ClassificationClassification

Purpose for classifying organisms

•brings order to the diversity of life

•allows identification of new organisms

•basis for scientifically naming organisms

•universal standard for communication

ClassificationClassification

common names can often be misleading

•jellyfish, starfish, cuttlefish, silverfish

ClassificationClassification

common names can often be misleading

•mountain lion, puma, cougar, panther

ClassificationClassification

common names can often be misleading

•ringworm, mealworm, acorn worm

fungusinsect larva

aquatic worm

ClassificationClassification

History of classification

•Aristotle (350B.C.)

–placed all known organisms into two groups

–animals & plants

ClassificationClassification

History of classification

•Carolus Linnaeus (1750)

–father of taxonomy

–classified organisms by

physical & structural similarities

–places organisms into Species

–places species into Genera

–introduced binomial nomenclature

•written in Latin (Genus, species)

ClassificationClassification

Correctly naming organisms scientifically

•First name: Genus (First letter CAPITALIZED)

•second name: Species (all lower case)

•underline (if hand written) or italicized (computer)

•ex: Eastern grey squirrel

–Sciurus carolinensis

ClassificationClassification

classification provides a framework in which to study the relationships among living and extinct species

ClassificationEvolutionary Relationships

structural similarities

•many shared physical structures provide evidence of close relationship and common ancestry

•ex: Lynx & Bobcat

ClassificationEvolutionary Relationships

structural similarities

•ex: dandelion & sunflower

ClassificationEvolutionary Relationships

geographical distribution

•location of a species help determine relationship with other species

•ex: finches on the Galapogos

ClassificationEvolutionary Relationships

chromosomal comparison

•chromosome number and shape

•ex: cauliflower, cabbage, kale, broccoli

•chromosomes are

almost identical

ClassificationEvolutionary Relationships

biochemistry

•looks at DNA and similar proteins

•ex: horseshoe crab

–originally classified with Crustacea

ClassificationEvolutionary Relationships

•ex: horseshoe crab

–originally classified with Crustacea

–better classified as Arachnida

ClassificationEvolutionary Relationships

Breeding behavior

•mating calls or mating periods

•ex: frogs, birds

ClassificationEvolutionary Relationships

•developing the

evolutionary history

of an organism is

phylogeny

ClassificationEvolutionary Relationships

•phylogeny of all life

ClassificationEvolutionary Relationships

•cladogram model

–shows evolutionary relationships between organisms

ClassificationEvolutionary Relationships

•cladogram model

AB

C

D

E

ClassificationTaxonomic Hierarchy•Domain – broadest classification•Kingdom•Phylum•Class•Order•Family•Genus•Species – most specific

–sometimes -subspecies (animals), •varieties (plants)•strains (bacteria)

•D K P C O F G S

ClassificationTaxonomic Hierarchyclassification of human?•Domain – Eukarya•Kingdom – Anamilia•Phylum – Chordata•Class – Mammalia•Order – Primate•Family – Homididae•Genus – Homo•Species – Sapien

–Binomial name?–Homo sapien

ClassificationHistory of Classification

1700’s

•Aristotle’s system

•Plantae & Animalia

ClassificationHistory of Classification

Late 1800’s

•with the use of the microscope, new kingdom was found

•Plantae, Animalia & Protista

ClassificationHistory of Classification

1950’s

•New tool - electron microscope, new kingdom was found without a nucleus

•Plantae, Animalia, Protista & Monera (bacteria)

ClassificationHistory of Classification

1960’s

•Biochemical studies showed difference in cell wall composition (split up one of our Kingdoms)

•Plantae, Animalia, Protista, Monera & Fungi

chitin

ClassificationHistory of Classification

1990’s

•Structural and biochemical studies found difference in cell wall of some Monerans •Plantae, Animalia, Protista, Archaebacteria, Eubacteria & Fungi

peptidoglycan

ClassificationCurrent System

3 Domain system

•developed from looking at ribosomal RNA

•Bacteria – Eubacteria

•Archea – Archaebacteria

•Eukarya – Plants, Animals, Fungi, Protista

ClassificationCurrent System

3 Domain system

ClassificationTools for classification

field guide

•gives physical description of species

•may show range (locations it lives in)

•gives picture of species

ClassificationTools for classification

dichotomous key

•uses sets of paired (usually opposite) traits to help classify a species

Geospiza CamarhynchusCerthideaPlatyspiza