Classification is the grouping of organisms according to characteristics
Taxonomy is the science of classifying organisms based on physical characteristics
Our taxonomic system was developed by Carolus Linneaus in the 1700’s
HumanBox Elder Tree
BobcatCanadian lynx
Kingdom Animalia Plantea Animalia Animalia
Phylum/Division Chordata Anthophyta Chordata Chordata
Class Mammalian Dicotyledonae Mammalia Mammalia
Order Primates Sapindales Carnivora Carnivora
Family Hominidae Aceracae Felidae Felidae
Genus Homo Acer Lynx Lynx
Species sapiens nugundo rufus canadensis
A domain is the highest level of taxonomic classificationThe three domains are Bacteria, Archaea, and EukaryaBacteria and Archaea are also names of kingdomsThe domain Eukarya contains the other 4 kingdoms of Protista, Fungi,
Plantae and Animalia
Classification often skips the domain and starts with the kingdoms shown below:
Archaea – separated from Monera in the 1990’s
Bacteria, also called Monera or EubacteriaProtistaFungiPlantaeAnimalia
The 6 Kingdoms
Each organism has a two part scientific name
The first name is the genus which is always capitalized
The second name is the species which is always lowercase
Names are in Latin because it was the language of scholars.
Each species has a unique scientific name but many organisms have a variety of common names
Scientific names of organisms are always italicized or underlined
For example Homo sapiens or Homo sapiensThe three ways to identify a species focus on
the biological species concept of fertile offspring, the phylogenetic species concept based on evolutionary history and the morphological species concept based on body features
Dichotomy---to divide in two A dichotomous key is commonly used by scientists to classify living organisms. At each step there are two alternatives offered, and the choice of one of those alternatives determines the next step.