classification

Classification taxonomy –science of grouping and naming organisms based on shared characteristics

WHY CLASSIFY ORGANISMS?

1.common names can often be misleading jellyfish, starfish, cuttlefish, silverfish

mountain lion, puma, cougar, panther

ringworm, mealworm, acorn worm fungus insect larva aquatic worm

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

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

History of Classification Aristotle (350B.C.) –placed all known organisms into two groups –animals & plants

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)

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

What Do We Use to Classify Organisms?

Evolutionary Relationships 1. Structural Similarities many shared physical structures provide evidence of close relationship and common ancestry ex: Lynx & Bobcat

Structural Similarities ex: dandelion & sunflower

Evolutionary Relationships 2. Geographical Distribution location of a species help determine relationship with other species ex: finches on the Galapogos

Evolutionary Relationships 3. Chromosomal Comparison chromosome number and shape ex: cauliflower, cabbage, kale, broccoli chromosomes are almost identical

Evolutionary Relationships 4. Biochemistry looks at DNA and similar proteins ex: horseshoe crab –originally classified with Crustacea

ex: horseshoe crab –better classified as Arachnida

Evolutionary Relationships 5. Breeding Behavior mating calls or mating periods ex: frogs, birds

Classification Evolutionary Relationships developing the evolutionary history of an organism is phylogeny

Classification Evolutionary Relationships phylogeny of all life

Classification Evolutionary Relationships cladogram model –shows evolutionary relationships between organisms

Classification Evolutionary Relationships cladogram model A B C D E

Classification History of Classification 1700’s Aristotle’s system Plantae & Animalia

Classification History of Classification Late 1800’s with the use of the microscope, new kingdom was found Plantae, Animalia & Protista

Classification History of Classification 1950’s New tool - electron microscope, new kingdom was found without a nucleus Plantae, Animalia, Protista & Monera (bacteria)

Classification History of Classification 1960’s Biochemical studies showed difference in cell wall composition (split up one of our Kingdoms) Plantae, Animalia, Protista, Monera & Fungi chitin

Classification History of Classification 1990’s Structural and biochemical studies found difference in cell wall of some Monerans Plantae, Animalia, Protista, Archaebacteria, Eubacteria & Fungi peptidoglycan

Classification Current System 3 Domain system developed from looking at ribosomal RNA Bacteria – Eubacteria Archea – Archaebacteria Eukarya – Plants, Animals, Fungi, Protista

Classification Current System 3 Domain system

Classification Taxonomic 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

Classification Taxonomic Hierarchy classification of human? Domain – Eukarya Kingdom – Anamilia Phylum – Chordata Class – Mammalia Order – Primate Family – Homididae Genus – Homo Species – Sapien –Binomial name? –Homo sapien

Classification Tools for classification field guide gives physical description of species may show range (locations it lives in) gives picture of species

Classification Tools for classification dichotomous key uses sets of paired (usually opposite) traits to help classify a species GeospizaCamarhynchusCerthideaPlatyspiza