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Taxonomy
 study of naming, identifying and classifying all
known species based on their similarities
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Species:
 a group of organisms that breed freely in nature,
and produce fertile offspring
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Whale Shark
Aardwolf
Starfish
Sealion
Crayfish
Tarantula Hawks
Guinea Pig
Others?
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Carolus Linnaeus (1700s): Father of Taxonomy
Problem with common names
Universal Classification: binomial
nomenclature
 Each species receives a unique two word scientific
name
 Based on: Morphology (physical similarities)
 Originally only 2 categories: Plants and Animals
Kingdom
General
Phylum
Class
Order
Family
Genus
Species
Specific
 Each
level is
known as
a taxon,
plural
taxa
Common Names:
Human
Nine-Banded
Armadillo
Kingdom:
Animalia
Animalia
Phylum:
Chordata
Chordata
Class:
Mammalia
Mammalia
Order:
Primata
Cingulata
Family:
Hominidae
Dasypodidae
Genus:
Homo
Dasypus
Species:
Homo sapiens
Dasypus novemcinctus
Scientific Names:
Novem= nine; -cinctus= band. Therefore “Nine-banded.”
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Morphology, or the structure of organisms is
not always enough to classify organisms
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What then?.....
Besides just morphology, Scientists also look
at:
 the evolutionary relatedness of organisms
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genetic information to determine relatedness
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Behaviour
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Chemical
Phylogeny: The
evolutionary history of a
species
 Phylogenetic Tree: A
diagram that illustrates
the evolutionary
relationships between
organisms
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tips represent species
nodes represent
common ancestor
Hagfish
Frog
Squirrel
Polar Bear
present
hair
limbs
past
vertebrae
Which animal is most closely related to the
squirrel?
Hagfish
Frog
Squirrel
Polar Bear
present
hair
limbs
past
vertebrae
Is the frog more distantly related to the polar
bear or the hagfish?
Hagfish
Frog
Squirrel
Polar Bear
present
hair
limbs
past
vertebrae
Is the hagfish more closely related to the polar
bear or the squirrel?
Hagfish
Frog
Squirrel
Polar Bear
present
hair
limbs
past
vertebrae
Which animals have limbs?
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A clade is a taxonomic group that includes a single
common ancestor and all its descendants
hagfish
frog
Squirrel
Polar Bear
Clade
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With your partner, determine all of the clades
present in the phylogenetic tree below
seal
bat
rat
rabbit
monkey
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International Barcode of Life Project (iBOL)
 Use DNA technology to create a DNA profile of
every species, in the form of a barcode
 Handheld device to quickly
identify any species from a tiny
sample of DNA
 5-100 million species on earth
▪ 6,000 profiled so far
At every level of classification, deciding which category
an organism belongs to involves comparing its
characteristics to the characteristics shared by the other
organisms in the level.
E.g. Panthera pardus
Phylum: spinal chord (Chordata) or no spinal
chord?
Class: warm-blooded? Nurse its young? Has fur?
(Mammalia)
Order: Adapted structures so they can eat flesh?
(Carnivora)
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A list of Yes or No Questions used by
scientists to identify relatedness
Level of classification depends on the detail
of the questions
Should be able to classify every organism
down to the species
IF what you are trying to classify doesn’t fit in
your key…
 You’ve discovered a NEW SPECIES!