Classification and Taxonomy

This is a baby tapir, closely related to a rhino.
Would you group them together in a zoo?

This is a elephant nosed shrew, closely related to a mole.

Taxonomy: The science of classifying organisms

Classification is about organizing life forms into groups.

How are zoos
organized?

How are your
drawers
organized?

How are
stores like Walmart
organized?

If you wanted a pair of blue, men's skinny Levi's, size 30x 36 You might find them using a thought process similar to this:

• Grocery or non grocery?

• Automotive, heath and beauty or clothing?

• Men's, women's or children's clothing

• Men's clothing worn on the top of your body or the bottom

• Jeans or non-jeans?

• Blue jeans or black jeans?

• Skinny or boot cut?

• Levi's or Wrangler?

• Size.....

Why do we need a standard way of naming organisms?

“Common names” can be confusing

The scientific name of a
Timber rattlesnake:

Crotalus horridus

Common Name?

Sea Lion?

Antlion?

Lion?

Which one of these is actually a bear?

What kind of organism is it?

(invertebrate, mammal, insect, fish, reptile..)

1.Sea Monkey
2.Firefly
3.Ringworm
4.Jellyfish
5.Spider monkey
6.Crayfish
7.Sea Horse

What kind of organism is it?

(invertebrate, mammal, insect, fish, reptile..)

1.Sea Monkey- not a monkey
2.Firefly- not a fly
3.Ringworm - not a worm
4.Jellyfish - not a fish
5.Spider monkey - not a spider
6.Crayfish- not a fish
7.Sea Horse - not a horse

Consider this………..

-Are all “Grey Wolves” gray?

-Are all “Black Bears” black?

- Which is more venomous, a water
moccasin or a cottonmouth?

Classification System

● Developed by Linnaeus

(Father of Taxonomy) in
the 1700’s who used
Greek and Latin names
to give every organism
has a unique name

● All organisms were placed into a few large groups called

- KINGDOMS -

● Since LInnaeus, we have added the DOMAIN level to

our hierarchical classification system

● In 1990, Carl Woese argued that the Archaea and

Bacteria were different enough (based on molecular
evidence) that they should be put into different groups
or DOMAINS

Domain
Kingdom

Phylum

Class

Order

Family

Genus

Species

Since Linneaus, we
have added the taxon

” Domain” as our

highest level

​Most diverse/general

​Most specific

To help you remember the list (in order from most general to most specific):

DUMB KING PHILLIP CAME OVER FOR GREAT

SPAGHETTI

Kingdom, Phylum, Class, Order, Family, Genus, Species

Domain

Eukarya

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Primate

Family

Hominidae

Genus

Homo

Species

sapiens

The scientific name is always the genus + species
Humans = Homo sapiens

Classification for Humans

Lion

Tiger

Pintail Duck

Kingdom

Animalia

Animalia

Animalia

Phylum

Chordata

Chordata

Chordata

Class

Mammalia

Mammalia

Aves

Order

Carnivora

Carnivora

Anseriformes

Family

Felidae

Felidae

Anatidae

Genus

Panthera

Panthera

Anas

Species

leo

tigris

acouta

What are the scientific names of each of these organisms?

The Classification of a Timber Rattlesnake

Domain

Eukarya

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Squamata

Family

Viperidae

Genus

Crotalus

Species

horridus

Which of these names represents a diamondback
rattlesnake (same genus as the Timber
Rattlesnake)?

a)

b)

c)

More on Naming..

The system of naming is called BINOMIAL NOMENCLATURE
- which means it is a 2-name system consisting of the genus
and species Ex. Homo sapiens

Rules:

1. Names must either be underlined or italicized

2. Genus capitalized, species is lowercase

3. Can be abbreviated. Ex. F. leo and T. rex

What is a species?

Defined as organisms that can interbreed with one
another, and produce fertile offspring

When two organisms of different species interbreed,
the offspring is called a HYBRID

Example: ligers and mules

Check for Understanding

1. Fill in the blanks: _____________, Kingdom, _____________,

Class, Order, ________________, Genus, _______________

2. Which two groups are used for an organism's scientific name?

3. Which of the following pairs is MOST closely related?


4. The system we use for naming is called ___________ nomenclature.

5. The science of classification is called ________________

3 Domains

● All organisms belong to

one of 3 domains,
depending on their
characteristics.

● A domain is the broadest,

most general taxonomic
category.

● A single domain can

contain one or more
kingdoms

Three Domain System

Three groups, called DOMAINS, contain the six kingdoms.

Domain Eukarya - includes organisms composed of eukaryotic cells
(plants, animals, fungi, protists)

Domain Bacteria - includes all
prokaryotic cells, Kingdom
Eubacteria

Domain Archaea - includes
only "ancient" bacteria,
Archaebacteria

Kingdoms based on:
-Number of cells (unicellular or multicellular)

-How it obtains energy
(heterotroph or autotroph)

-Type of cell (eukaryote or prokaryote)

The Kingdoms

There are currently 6 kingdoms

Kingdom Animalia

Multicellular, Eukaryote

Heterotrophic, No cell wall

Most can move

Examples: birds, insects,
worms, mammals, reptiles,
humans, anemones

Kingdom Plantae

Multicellular, Eukaryotic

Autotrophic, Cell wall of
cellulose

Cannot move

Kingdom Fungi

Multicellular (most), Eukaryotic

Heterotrophic (mainly decomposers),
Cell wall of Chiten

Kingdom Protista

● Most are unicellular
● Most live in water
● Can be heterotrophic or

autotrophic

● Most with cell wall
● Eukaryotes (all have nucleus)

Examples: Ameba, paramecium, algae (
sea weed & kelp)

The Prokaryotes (do not have a nucleus)

Unicellular

Can be autotrophic or heterotrophic

Have a cell wall

Kingdom:Eubacteria = common
(E. coli, Salmonella)

Kingdom:Archaebacteria = “ancient bacteria”,exist in extreme environments

Archebacteria

Extremophiles (live in extreme environments:
● Thermophiles ( extreme hot & cold)
● Halophiles (extremely salty)
● Methanogens ( produce methane)

● Prokaryotic
● Cell wall ( no

peptidoglycan)

● Anaerobic
● Human gut and mouth

Eubacteria

● Prokaryotic
● Peptidoglycan Cell

wall

● Aerobic &

Anaerobic

● Human gut and

mouth

● Most are harmless
● Ubiquitous!

Modern Taxonomy
Clades and Keys

A clade is just a fancy name
for a group