Classification
What does classification mean? Write your answer using a complete sentence.
What is Classification? It is the arrangement of objects, ideas, or information into groups by finding common traits or characteristics.
Purpose of Classification The reason is to logically organize the approximately 1.5 million species that we have on earth. The classification of these species is based on their DNA component, development, reproduction, morphology and physiology.
The History of Organization Aristotle BCE Interested in biological classification. Patterns in nature. Carl Linnaeus CE Father of Biological Classification!
Binomial Nomenclature Carolus Linneaus developed a two- word naming system called binomial nomenclature. The system involves the assigning of a two-part scientific name to each species.
Binomial Nomenclature The two-part scientific name consist of the name of the genus [ the first one] and the name of the specific epithet [the second one]. Both are underlined when written or in italics when typed.
Two-part Scientific Name The first is capitalized and the second in lower case. The two make up the name of the species. Examples:Homo sapiens, Drosophila melanogaster Sometimes, the first name may be abbreviated (ex. Escherichia coli could be written as E. coli)
Common name: Black and Polar Bear Ursus americanus Ursus maritimus
Why Latin is used in naming species? i.Common names are not universal and meanings of words change over time –“Possums” in America are NOT possums in Australia (Didelphis virginiana versus Trichosurus vulpecula) IiLatin is used because is it universally understood and being a “dead language” it will not change over time.
The Science of Classification Scientist who classify or organize organisms (animals and plants) into related groups are called taxonomists. Taxonomist study taxonomy and the groupings are called “taxa”
Table Talk/Discussion Session (1)Who was Carolus Linneaus? (2)Explain what is meant by binomial nomenclature [ give an example] (3)Why is Latin used in naming species?
Groups are also arranged in hierarchical order.
Linnaeus Hierarchical System of Classification Largest to Smallest: Taxonomic categories Domain Kingdom (big) Phylum Class Order Family Genus species
Mnemonic Device In the margin of your paper, create your own sentence to help you remember the order of classification. Dear King Philip Came Over For Good spaghetti Dracula Kills People’s Children On Fridays, Get scared!
Taxonomy Grizzly bearBlack bearGiant panda Red fox Albert squirrel Coral snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos Most specific Least specific
Most specific Least specific
New Discoveries Questions How can you answer these questions? Why is Taxonomy Important? Unknown species discovered. New fossil Uncovered.
The White Board Session Which taxonomic group is the most broad. (Is the largest?) Kingdom
The White Board Session What 2 parts make up the species name? Genus & Specific Epithet
The White Board Session Which taxonomic group is the most specific? Species
The White Board Session Which taxonomic group is more specific than order but broader than genus? Family
Cladograms/ Phylogenetic Trees a.They are diagrams showing evolutionary relationships (family tree of species) b.Constructed using morphology and DNA evidence to order the organisms in sequence.
Cladograms/ Phylogenetic Trees c.Important features: i.Derived characteristics- recently evolved characteristics of organisms being compared ii.Ancestral characteristics- shared characteristics of all the organisms being compared
Define the derived and ancestral characteristics.
Is the rabbit more closely related to the primates of the ray-finned fish? Primates
Define the derived and ancestral characteristics. To what are dinosaurs and birds most closely related? Crocodiles