Classification and Taxonomy

• Classification arranges organisms into orderly groups based on similarities
• Classification is also known as taxonomy
• Taxonomists identify and name organisms

Benefits of Classification

• Classification accurately and uniformly names organisms
• Classification prevents misnomers, like classifying starfish and jellyfish as fish
• Classification uses the same language (Latin or Greek) for all names

Early Taxonomists

• Aristotle was the first taxonomist around 2000 years ago
• Aristotle divided organisms into plants and animals
• Aristotle subdivided organisms by habitat into land, sea, or air dwellers

Carolus Linnaeus

• An 18th-century taxonomist classified organisms by structure
• Linnaeus developed binomial nomenclature, a two-word naming system (Genus and species) still used today
• Linnaeus is called the Father of Taxonomy

Binomial Nomenclature

• It uses Genus species
• Binomial Nomenclature is Latin or Greek
• It is italicized in print
• It is underlined when writing
• Genus is capitalized, but the species is not

Classification Groups

• A Taxon (taxa-plural) is a category into which related organisms are placed
• Hierarchy of groups (taxa) goes from broadest to most specific
• The groups in order of broadest to most specific are Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Domains

• The broadest and most inclusive rank in biological taxa is domain
• The three domains are Archaea, Bacteria, and Eukarya
• Archaea and Bacteria are unicellular prokaryotes lacking a nucleus or membrane-bound organelles
• Eukarya are complex and have a nucleus and membrane-bound organelles

Domain Archaea

• Consists of unicellular organisms
• Archaea are prokaryotes, therefore lack a nuclear membrane
• They are found in extreme environments like salty water and volcanic hot springs
• An example of an Archaea is Sulfolobus which grows in volcanic springs
• They belong to the Kingdom: Archaebacteria

Domain Bacteria

• Bacteria are found everywhere
• Bacteria are prokaryotes, therefore lack a nuclear membrane
• Bacteria is the most known and studied
• An example of a Bacteria is Streptococcus which cause strep throat
• They belong to the Kingdom: Eubacteria

Domain Eukarya

• Found everywhere
• Most of the world's living things.
• Eukaryotes have cells with a nucleus
• Humans are an example
• The following Kingdoms are in Eukarya: Protista, Fungi, Animalia, and Plantae

Kingdom Eubacteria

• Consists of true bacteria
• Eubacteria are prokaryotic
• Eubacteria are unicellular
• They can be Autotrophs and/or Heterotrophs
• They are spherical or rod-shaped
• Eubacteria are found in soil, rocks, oceans, snow, and living organisms

Kingdom Archaebacteria

• This differs from other bacteria
• Archaebacteria are prokaryotic and unicellular
• They can be Autotrophs and/or Heterotrophs
• They are found in hydrothermal vents

Kingdom Protista

• Organisms can not be classified as an animal, plant, or fungus
• Protista are eukaryotes
• Protista are mostly unicellular
• They can be Autotrophs and/or Heterotrophs
• Slime mold, protozoa, and primitive algae are examples

Kingdom Fungi

• Fungi is multicellular
• Fungi are Eukaryotes
• Consists of all heterotrophs
• Yeast, mushrooms, and ringworm are examples

Kingdom Plantae

• Consists of multicellular organisms
• Plantae are eukaryotes
• Most live on land
• Plantae are Autotrophs and make their own food
• They provide food for heterotrophs

Kingdom Animalia

• Animalia are multicellular
• Animalia are Eukaryotes
• They live everywhere
• Animalia are heterotrophs and consumers

Cladograms

• A cladogram is a tree-like diagram showing evolutionary relationships
• Cladograms contain clades
• Some clades are nested together
• Derived characteristics appeared in recent parts of the lineage but not in older members
• A cladogram shows the order in which derived characteristics evolved
• Cladograms are made from a table that shows derived characteristics
• Shared characteristics are those shared among multiple organisms
• Cladograms include: outgroup, ingroup, sister clade/group, common ancestor, and node

Phylogenetic Trees

• Phylogenetic tree is a branching diagram, or "tree," showing the evolutionary relationships among biological species or entities, their phylogeny, based on similarities and differences in their physical or genetic characteristics