Taxonomy (Classification) and

Phylogeny (Cladistics)

• Classification is the grouping of

objects based on physical similarities. In

biology when doing this with organisms,

it is called taxonomy.

• It is predominately based on

morphology.

• Linnaeus and Whittaker gave us this

system

• Classifies diverse organisms into “like

groups” based on traits. As the traits

become more specific, fewer and fewer

organisms are together.

Linnaean Taxonomic Classification

Kingdom

Phylum

Class

Order

Family

Genus

Species

Three Domain system was later

introduced.

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

The Three Domains

• Domain Archaea– Ancient prokaryotes

• Domain Bacteria– Modern prokaryotes

• Domain Eukarya- all eukaryotic

cells– plantae, animalia, fungi, protista

Think - Pair - Share

What is types of organisms would be

found in each of the Kingdoms?

The domain eukarya is very diverse …WHY???

• Taxonomists give a unique scientific

name to each species they know

about whether it’s alive today or

extinct. (not to be confused with

taxidermist)

• The scientific name comes from one

of two “dead” languages – Latin or

ancient Greek.

• Why use a dead language?

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Puma

Florida Panther

Cougar

• There are at least 50 common

names for the animal shown on the

previous 7 slides.

• Common names vary according to

region.

• Soooo……that’s why we use a

scientific name, based on Latin!

Binomial Nomenclature• a two part naming system for writing scientific

names.

• The genus name is written first (always

Capitalized)

• The species name is written second (never

capitalized).

• Both words are

– italicized if typed or underlined if hand

written.

FELIS CONCOLOR

– Felis concolor or F. concolor

– Apply: Which is the genus? The species?

• Cladistics /Phylogeny- is a relatively

new system of classification that uses

shared derived traits to establish

evolutionary relationships.

• A derived trait is a feature that evolved

only within the group under

consideration.

• A phylogenetic tree based on a

cladistic analysis is called a cladogram.

• Out-group is the least related group, will

be found on the far left of our

diagrams!

• Synapomorphies = derived

characteristics

• Clade = A group of organisms and

their common ancestor.

Think – Pair - Share

• What is a shared derived trait that

humans have?

• Talk with the person next to you,

come up with a couple of ideas.

• Be ready to share!

Who is the most derived? Who is the out-group?

What is a shared derived trait for pigeons?

What is a shared derived trait for mammals?

Where would you put monkeys?