Biological Classification

Why classify? Humans have developed classification systems in order to make sense of the abundant biological diversity that exists in nature.

Taxonomy …the identification, naming, and classification of species Taxonomists spend their time searching for previously unknown organisms, determining their relationships to known organisms, and giving them names.

The Linnaean System of Classification The system is hierarchical. Larger groups are more general and smaller groups are more specific. For example, the phylum Chordata includes both lions and lionfish, but the genus Panthera includes only lions. Chordata Panthera

The Linnaean System of Classification The system is phylogenetic. It is meant to reflect the evolutionary interrelatedness among groups. For example, the grey wolf and the dog both are placed in the genus Canis because of their close evolutionary relationship. Homologous structures are the clues used to assess how closely organisms are related. grey wolf dog

Seven Levels of Taxonomic Classification Kingdom Phylum Class Order Family Genus Species Seven Levels of Taxonomic Classification

“Kansas Predators Catch Old Furry Grey Squirrels” Kingdom, Phylum…what? An easy way to remember the classification levels: “Kansas Predators Catch Old Furry Grey Squirrels” Try to make up your own!

Seven Levels of Taxonomic Classification for the… Kingdom Phylum Class Order Family Genus Species Seven Levels of Taxonomic Classification for the… Grizzly Bear

Kingdom The most general of the seven levels. Traditionally, biologists have recognized five different kingdoms: Monerans, Protists, Fungi, Plants, Animals

Phylum (plural: phyla) Each kingdom is subdivided into smaller, more specific groups called phyla.

Class Each phylum is subdivided into smaller groups called classes.

Order Each class is subdivided into smaller groups called orders.

Family Each order is subdivided into smaller groups called families.

Genus (plural: genera) Each family is subdivided into smaller groups called genera.

Species Each genus is subdivided into smaller groups called species. The species is the most specific level of classification.

Scientific Names The scientific name (binomial) of an organism contains two parts—the name of the genus and the name of the species.

Writing Scientific Names The rules for writing scientific names: -CAPITALIZE the first letter of the genus name. -Do not capitalize the species name. -Both names must be underlined or italicized. Example: human = Homo sapiens

Seven Levels of Taxonomic Classification for the… Kingdom-Animalia Phylum-Chordata Class-Mammalia Order-Carnivora Family-Felidae Genus-Panthera Species-leo Seven Levels of Taxonomic Classification for the… Lion

Seven Levels of Taxonomic Classification for the… Kingdom-Animalia Phylum-Chordata Class-Mammalia Order-Primates Family-Hominidae Genus-Homo Species-sapiens Seven Levels of Taxonomic Classification for the… Human

Seven Levels of Taxonomic Classification for the… Kingdom-Animalia Phylum-Chordata Class-Mammalia Order-Carnivora Family-Canidae Genus-Canis Species-familiaris Seven Levels of Taxonomic Classification for the… Dog

Seven Levels of Taxonomic Classification for the… Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Xenarthra Family: Myrmecophagidae Genus Tamandua Species: tetradactyla Seven Levels of Taxonomic Classification for the… Collared Anteater