Classification

Basic Definitions Classificationthe grouping of objects/information based on similarities Taxonomythe branch of biology concerned w/grouping & naming organisms

Early Naming Systems Based on edible or toxic Aristotle – 1st system in 300 B.C. plants vs. animals based on sizes & locations Carolus Linneus - 1700’s based on body structures Still used today

Binomial Nomenclature Genussmall group closely related organisms Speciesdescribes an important characteristic of the organism G + S  Scientific name Humans?

Examples Ursus maritimus Ursus arctos Genus-Ursus = bear Species-maritimus = sea Species-arctos = great northern/grizzly

Scientific Names Reduces confusion caused by common/local names Scientific committee -consistency & preserves one of each species Latin – dead language (words don’t change meaning) & basis for other languages

Example In USA & England - house sparrow In Spain - gorrion In Holland – musch In Sweden – hussparf Scientific Name - Passer domesticus

Rules for writing Scientific Names First letter of genus - ALWAYS capitalized First letter of species - NEVER capitalized Scientific names are italicized (if typed) or underlined (if hand written)

Which of these are written correctly? Viola tricolor (pansy with 3-colored flower) Quercus phellos (Willow Oak) Nymphaea ordata (fragrant water lily) Clostridium Botulinum (bacteria that causes a form of food poisoning) homo sapiens

4 Rules for assigning scientific names All scientific names must be Latin words or terms constructed according to the rules of Latin grammar. Two different organisms cannot be assigned the same scientific name.

Rules continued… For each member of the same genus, the second word (species name) must be different. Organisms in different genera will NOT have the same genus name, BUT can have same species name.

Domains (3) Family Genus Species Kingdom (6) Phylum Order Class

Grizzly bear Black bear Giant panda Red fox Abert squirrel Coral snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos

Classification System The smallest group/TAXA is the species. If they share many features but are clearly different species, they are classified as different species within the same genus.

Example House cat(Felis domesticus) & the mountain lion (Felis concolor) Lions placed in a separate genus, Panthera leo

Groups of similar genera are put into the same family. Ex: All genera with cat-like characteristics are put in the family of Felidae.

Families of similar organisms are placed in the same order. Ex: Cats are in the same order as dogs—Carnivora—they are all meat eaters.

Similar orders are grouped into the same class. All warm-blooded animals that have body hair and produce milk for their young are in the class Mammalia.

Similar classes are grouped into the same phylum. (Plants – divisions) Mammals are placed in the same phyla as reptiles and fishes-Chordata. Similar phyla are grouped into the same kingdom. 6 kingdomsArchaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia.

In review… Kingdom Phylum Class Order Family Genus Species King Philip Came Over For Good Soup Kings Play Chess On Fuzzy Green Stools

Importance of Taxonomy Drugs for diseases Invasive & toxic organisms Earth friendly cleaning products

Classification Today Evolutionary classification, not just physical characteristics. Relationships determined by structure, development, biochemistry, and behavior. Phylogeny - the evolutionary history of a species; can be illustrated on a cladogram or phylogenic tree

Reading a cladogram/phylogeny Each branch represents an evolutionary lineage Implied in the x direction is some sort of evolutionary distance from each other and implied in the y direction is relative time Intersecting lines represent a speciation event

3 Domains

Practice Problems

Your turn

Cladogram – shows evolutionary relationships

3 Domains DOMAIN ARCHAEA DOMAIN EUKARYA DOMAIN BACTERIA Eubacteria Archaebacteria Protista Plantae Fungi Animalia DOMAIN EUKARYA DOMAIN ARCHAEA DOMAIN BACTERIA

Dichotomous Key Set of paired statements that describe physical characteristics of different organisms. Used to identify organisms