Taxonomy (Classification)

Carolus Linnaeus -developed the scientific naming system still used today.

Taxonomy is the science of naming and classifying organisms.

• A taxon is a group of organisms in a classification system.

White oak:Quercus alba

Binomial nomenclature is a two-part scientific naming system.

– uses Latin words (universal, unchanging language)– scientific names always written in italics or underlined– two parts are the genus name and species

o Genus is the first part of a scientific name.o Genus name is always capitalized.

o A species is the second part of a scientific name.o always lowercaseo always follows genus

name; never written alone

o Scientific names are written in

italics or underlined

Tyto alba

– Some species have very similar common names.– Some species have many common names.

Scientific names help scientists to communicate.

Rhinecanthus aculeatus

- Hawaii – Huma Huma Nuka Nuka Apua’a

- Other Places - Picasso Triggerfish

Linnaeus’ classification system has seven levels.

Each level is included in the level above it.

• Levels get increasingly specific from kingdom to species.

• Kingdom, phylum, class, order, family genus, species

Levels of Classification

1. Kingdom-largest (least specific)

2. Phylum

3. Class

4. Order

5. Family

6. Genus

7. Species-smallest (most specific)

These levels are called taxa (plural for taxon).

Classifying people!

1. Kingdom – Animal2. Phylum – Chordate (backbones)3. Class – mammal4. Order - Primates5. Family - Hominidae6. Genus – Homo (man)7. Species –sapiens (wise)Scientific Name of people: Homo sapiens

How do I remember the order?

* Use the sentence:Kings Play Chess On Funny Green Squares

OR

Keep Players Calm Or Fight Gangster Style

OR

King Philip Came Over For Good Soup

The Linnaean classification system has limitations.

Linnaeus taxonomy doesn’t account for molecular evidence. The technology didn’t exist during Linneaus’ time. Linnaean system based only on physical similarities.

• Physical similarities are not always the result of close relationships.

• Genetic similarities more accurately show evolutionary relationships.

• DNA shows red panda to be more related to raccoon than pandas

• 1992 rainbow trout Salmo gairdneri was reclassified as Oncorhynchus mykiss because molecular evidence shows it is more closely related to salmon

Cladistics is classification based on common ancestry.

Phylogeny- evolutionary relationships among organisms that show descent from a common ancestor, not similarities based off of physical characteristics.o evidence from living species, fossil record, and molecular datao shown with branching tree diagrams

Phylogeny

A cladogram is a graphic that shows the evolutionary relationships among a group of

organisms.

Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification.

Until 1866: only two kingdoms,Animalia and Plantae

Animalia

Plantae

Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification.

Until 1866: only two kingdoms,Animalia and Plantae

– 1866: all single-celled organisms moved to kingdom Protista

Animalia

Protista

Plantae

Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification.

Until 1866: only two kingdoms,Animalia and Plantae

– 1938: prokaryotes moved to kingdom Monera

– 1866: all single-celled organisms moved to kingdom Protista

Animalia

Protista

Plantae

Monera

The tree of life shows our most current understanding. New discoveries can lead to changes in classification.

Until 1866: only two kingdoms,Animalia and Plantae

Classification is always a work in progress.

– 1938: prokaryotes moved to kingdom Monera

– 1866: all single-celled organisms moved to kingdom Protista

Monera– 1959: fungi moved to own

kingdom

Fungi

Protista

Plantae

Animalia

The tree of life shows our most current understanding. New discoveries can lead to changes in classification.

Until 1866: only two kingdoms,Animalia and Plantae

Classification is always a work in progress.

– 1938: prokaryotes moved to kingdom Monera

– 1866: all single-celled organisms moved to kingdom Protista

– 1959: fungi moved to own kingdom

– 1977: kingdom Monerasplit into kingdoms Bacteria and Archaea

Animalia

Protista

Fungi

Plantae

Archea

Bacteria

There are 3 domains and 6 kingdoms

Domain Bacteria Kingdom Eubacteria

Domain Archaea Kingdom Archaebacteria

Domain Eukarya Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia

Domain Bacteria—Kingdom Eubacteria

Cell type: ProkaryoteCell structures: Cell walls with

peptidoglycanNumber of cells: UnicellularMode of nutrition: Autotroph

or HeterotrophExamples: Streptococcus, E.

coliEubacteria live everywhere.

They inhabit your mouth, your skin, your stomach, dirt, desks, floors, etc..

These are the common bacteria that we refer to as germs.

Streptococcus mutans(can cause endocarditis and dental caries)

Bacillus anthracis(spores can live in soil for years)

Domain Archaea—Kingdom Archaebacteria

Cell type: ProkaryoteCell structures: Cell walls

without peptidoglycanNumber of cells: UnicellularMode of nutrition: Autotroph

or HeterotrophExamples: Methanogens,

halophiles, thermophilesArchaebacteria live in very

EXTREME environments. They inhabit volcanic hot springs, black mud with no oxygen, and very salty water.

These are the extreme bacteria that we do not come in contact with frequently.

Domain Eukarya includes all eukaryotes.

– kingdom Protista

– kingdom Protista

– kingdom Plantae

Domain Eukarya includes all eukaryotes.

– kingdom Protista

– kingdom Plantae

– kingdom Fungi

Domain Eukarya includes all eukaryotes.

– kingdom Protista

– kingdom Plantae

– kingdom Fungi

– kingdom Animalia

Domain Eukarya includes all eukaryotes.

Kingdom Protista

Cell type: EukaryoteCell structures: Some have cell

walls of cellulose and some have no cell walls

Number of cells: Most unicellular; some multicellular

Mode of nutrition: Autotroph or Heterotroph

Examples: Amoeba, Paramecium, slime molds, giant kelp, algae

Protists display the greatest variety. If something can’t be classified as anything else, it is placed in this category.

All protists live in some type of water or moist environment (like in moist soil or in your own body!)

Kingdom Fungi

Cell type: EukaryoteCell structures: Cell walls of

chitinNumber of cells: Most

multicellular; some unicellular (like yeast)

Mode of nutrition: Heterotroph

Examples: Mushrooms, yeast, mildew

Fungus is important! We can eat some and it can help make bread, but it can also cause athlete’s foot and other fungal infections.

They like moist environments.

Kingdom Plantae

Sunflowers in Fargo, North Dakota

Cell type: EukaryoteCell structures: Cell walls of

cellulose; have chloroplastsNumber of cells:

MulticellularMode of nutrition:

AutotrophExamples: Mosses, ferns,

flowering plantsPlants are non-motile, which

means they cannot move from place to place

Kingdom Animalia

Cell type: EukaryoteCell structures: No cell

wallsNumber of cells:

MulticellularMode of nutrition:

HeterotrophExamples: Sponges,

worms, insects, fishes, mammals

Very diverse!

DOMAIN KINGDOM EXAMPLES

Bacteria Eubacteria Streptococcus, Escherichia coli

Archaea Archaebacteria Methanogens, halophiles

Eukarya Protist Amoeba, paramecium, slime molds, giant kelp

Fungi Mushrooms, yeasts

Plantae Mosses, ferns, flowering plants

Animalia Sponges, worms, insects, fishes, mammals