Taxonomy (Classification)
Carolus Linnaeus -developed the scientific naming
system still used today.
 Taxonomy is the science of naming and classifying
organisms.
White oak:
Quercus alba
•
A taxon is a group of organisms in a classification system.
 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 lowercase
o always follows genus
name; never written alone
o Scientific names are written in
italics or underlined
Tyto alba
Scientific names help scientists to communicate.
– Some species have very similar common names.
– Some species have many common names.
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 – Animal
2. Phylum – Chordate (backbones)
3. Class – mammal
4. Order - Primates
5. Family - Hominidae
6. 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
o
evidence from living species, fossil record, and molecular data
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
Animalia
– 1866: all single-celled organisms
moved to kingdom Protista
Plantae
Protista
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
– 1866: all single-celled organisms
moved to kingdom Protista
Plantae
Protista
– 1938: prokaryotes moved to
kingdom Monera
Monera
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
Plantae
Animalia
– 1866: all single-celled organisms
moved to kingdom Protista
Protista
– 1938: prokaryotes moved to
kingdom Monera
– 1959: fungi moved to own
kingdom
Monera
Fungi
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
Plantae
Animalia
– 1866: all single-celled organisms
moved to kingdom Protista
Protista
– 1938: prokaryotes moved to
kingdom Monera
– 1959: fungi moved to own
kingdom
Archea
Fungi
– 1977: kingdom Monera
split into kingdoms Bacteria and Archaea
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: Prokaryote
 Cell structures: Cell walls with





peptidoglycan
Number of cells: Unicellular
Mode of nutrition: Autotroph or
Heterotroph
Examples: Streptococcus, E. coli
Eubacteria 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: Prokaryote
 Cell structures: Cell walls without





peptidoglycan
Number of cells: Unicellular
Mode of nutrition: Autotroph or
Heterotroph
Examples: Methanogens, halophiles,
thermophiles
Archaebacteria 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
Domain Eukarya includes all eukaryotes.
– 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
Kingdom Protista
 Cell type: Eukaryote
 Cell 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: Eukaryote
 Cell structures: Cell walls of chitin
 Number 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
 Cell type: Eukaryote
 Cell structures: Cell walls of




cellulose; have chloroplasts
Number of cells: Multicellular
Mode of nutrition: Autotroph
Examples: Mosses, ferns,
flowering plants
Plants are non-motile, which
means they cannot move from
place to place
Sunflowers in
Fargo, North Dakota
Kingdom Animalia
 Cell type: Eukaryote
 Cell structures: No cell walls
 Number of cells: Multicellular
 Mode of nutrition: Heterotroph
 Examples: Sponges, worms,
insects, fishes, mammals
 Very diverse!
DOMAIN
KINGDOM
EXAMPLES
Bacteria
Eubacteria
Streptococcus,
Escherichia coli
Archaea
Archaebacteria
Methanogens,
halophiles
Protist
Amoeba, paramecium,
slime molds, giant kelp
Fungi
Mushrooms,
yeasts
Plantae
Mosses, ferns,
flowering plants
Animalia
Sponges, worms,
insects, fishes,
mammals
Eukarya