Taxonomy is the field of Biology thatdeals with classifying organisms

• Organisms are placed into categories based onshared characteristics

• Organisms that are more closely related areplaced in the same or similar categories

Carolus Linneaus devised a system forclassifying organisms in the mid 1700’s

• He created taxa that were based on similar orhomologous structures

• The broadest and largest taxon is called aKingdom, while the smallest is called a species

• Every organism was given a scientific name usingthe genus and species Ex: Homo sapiens or Canus lupus

Common names differ from place to place Ex: Crayfish, Crawdaddy, & Crawfish

Common names do not always accuratelydescribe the specimen

Ex: A jellyfish is not a fish (nor is it jelly)

Common names are too general Ex: “Oak Tree” – there are many different species of

oak trees

Identifying organisms by their genus andspecies name (Scientific Name) is calledBinomial Nomenclature.

• This literally translates to two-name namingsystem

• Scientific names are used to create a UniversalLanguage

• Rules for writing a scientific name: Use a capitalized Genus and lower case species Both of them will be italicized or underlined

Example: Homo sapien

All organisms are classified in ahierarchical system of groups that increasein inclusiveness

There are seven taxa (groups) into whichorganisms are placed:

• Kingdom, Phylum, Class, Order, Family,Genus, and Species

You may use a pneumonic to rememberthe taxa

• Ex: King Phillip Came Over For Good Spaghetti• Ex: King Phillip Came Over For Gumbo Soup• Ex: Kings Play Cards On Flat, Green Stools

EXTRA CREDIT: Try to come up with yourown pneumonic (be creative, but also

make sure it is easy to remember!)

The Species is the basic biological unit inthe modern classification system

Species are organisms that can interbreedand produce fertile offspring

• Ex: Killer Whales

• There are always exceptions: Mules, Ligers, Tigons (are sterile hybrids)

Monera

• Characteristics: Unicellular Heterotrophic or

Autotrophic Prokaryotic

• Ex: Bacteria

Protista

• Characteristics Unicellular Heterotrophic &

Autotrophic Eukaryotic

• Ex: Paramecium &Algae

Fungi

• Characteristics: Multicellular or

Unicellular Heterotrophic Eukaryotic

• Ex: Mushrooms &Yeast

Plantae

• Characteristics: Multicellular Autotrophic Eukaryotic

• Ex: Trees, Roses, Moss

Animalia

• Characterisitics: Multicellular Heterotrophic Eukaryotic

• Ex: Mammals,Insects, Birds, Fish,Coral

The Six Kingdoms of Living Things:

1. Animals2. Plants3. Fungi4. Protists5. Archaebacteria (aka Monera)6. Eubacteria (aka Monera)

The basis for classification is very similar to thebasis for evolutionary relationships

Physical traits (called morphology) oforganisms, such as homologous structures,are used to determine evolutionary relationships• Ex: a Human’s Arm, a Bat’s Wing & a Whale’s Flipper

A more exact method is Biochemical Analysis• See how similar the DNA is of different organisms

A family, or phylogenetic tree, showsrelationships among organisms

• The organisms at the tip of the branches are morerecently evolved

• The organisms at the base of the tree are theoldest

• Each time a branch divides, a new species hasemerged

A cladogram is a branching structurethat shows shared traits of organisms

A cladogram can show differences inanatomy, physiology, or behavioramong organisms

A dichotomous key is a type ofclassification key• It is a tool for identifying unfamiliar organisms

It is a list of observable traits that willlead you to the identity of the organism• The common name, as well as, the scientific name

of the organism is usually obtained

Heron Mosquito Mayfly