Taxonomy (Classification) and
• 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
• Classifies diverse organisms into “like
groups” based on traits. As the traits
become more specific, fewer and fewer
organisms are together.
8 Levels of taxonomy….self check!
Let’s look at the 8 Levels of taxonomy
one more time!
The Three Domains
• Domain Archaea
– Ancient prokaryotes
• Domain Bacteria
– Modern prokaryotes
• Domain Eukarya- all eukaryotic cells
– plantae, animalia, fungi, protista
Before we move on…protista???
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
• Why use a dead language?
• 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!
• a two part naming system for writing scientific
• The genus name is written first (always Capitalized)
• The species name is written second (never
• Both words are
– italicized if typed or underlined if hand written.
– 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
• 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
Think – Pair - Share
• What is a shared derived trait that humans
• 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?