CLASSIFICATION
Why Classification?
* Study the diversity of life
* Group and name organisms in a
logical manner
Taxonomy: science of classifying living
and creating scientific names
Early Classification
Aristotle: 350 B.C.
* Greek philosopher who classified
organisms into two kingdoms: Plants or
Animals
Plants: size and structures
Animals: behavior and habitat
* What might be some problems with his
system?
Video Clip
http://www.glencoe.com/sec/science/biology/
bio2000/biomovies/e20_1int.html
Linneaus: Mid 1700s:
developed a new
classification system
His system grouped
organisms based on
morphology (physical
appearance)
Created 7 taxonomic
levels
Carolus Linnaeus
(1707-1778)
Linnaeus’ Taxonomic levels
7 taxonomic levels (taxon=category) :
Kingdom, Phylum, Class, Order, Family,
Genus, Species
Phrase to remember order of levels:
King Phil Came Over For Good Soup
7 Taxonomic levels
Can be compared to our address system
Kingdom (broadest)----- Country
Phylum -------------------- State
Class----------------------- County
Order -------------------- City
Family -------------------- Zip Code
Genus -------------------- Street
Species (most specific)- House #
Leopard
Human Taxonomy
Kingdom
Animalia
-many cells (multicellular)
-cells have a nucleus
- don't have any chlorophyll
Phylum
Chordata
-had NOTOCHORD. That's a rod made
out of cartilage.
Class
Mammalia
-warm blooded
-nurse young
-hair
Order
Primata
-eyes on the front of the head
Family
Hominidae
-walk upright
-no tail
-s shaped spine
Genus
Homo
Species
sapien
ORGANISM
GROUP NAME
HUMAN
CHIMPANZEE
HOUSE
CAT
LION
HOUSEFLY
KINGDOM
Animalia
Animalia
Animalia
Animalia
Animalia
PHYLUM
Chordate
Chordate
Chordate
Chordate
Arthropoda
CLASS
Mammal
Mammal
Mammal
Mammal
Insect
ORDER
Primates
Primates
Carnivora
Carnivora
Diptera
FAMILY
Hominidae
Hominidae
Felidae
Felidae
Muscidae
GENUS
Homo
Pan
Felis
Felis
Musca
SPECIES
sapiens
troglodytes
domestica
leo
domestica
Scientific
Name
Homo
sapiens
Pan
troglodytes
Felis
domestica
Felis
leo
Musca
domestica
What is a Species?
Group of similar organisms that
reproduce NATURALLY, with consistent
pregnancies, and create FERTILE
offspring
Binomial Nomenclature
Scientific Names
Scientists avoid using common names to prevent
confusion because they vary from region to
region.
Blue Jay
Eastern Blue Jay
Cyanocitta cristata
Blue Jay
Western Blue Jay
Cyanocitta stellari
Binomial Nomenclature
Scientific Names
2 part naming system that consists of genus
and species.
Rules for writing scientific names:
Genus: first word - first letter capitalized
Species: second word - lowercase
Both are underlined or italicized
EX: Homo sapiens : Human beings
Sialia sialis: Eastern Bluebird
North American Pocket Mice
Pergonathus californicus
Found in California
Pergonathus nelsoni
Discovered by someone named Nelson
Pergonathus spinatus
Has prickly fur
Common Factors-Same genus, different
species, so would produce infertile
offspring.
Review
What are the eight characteristics of
life?
Living things are made of cells
Must reproduce
Same genetic code
Must grow and develop
Must obtain energy
Must respond to environment
Must maintain homeostasis
Must adapt and evolve
Review
What are the 7 taxonomic levels in
order from most general to most
specific?
Kingdom
Phlyum
Class
Order
Family
Genus
Species
Review
Who created the classification system
that is currently in use?
Linnaeus
Review
The two name scientific naming system
for organisms is called ____________.
Binomial nomenclature
Review
Which taxon comes first in a scientific
name?
Genus
Review
How should you format the scientific
name?
Genus- capitalized
Species-lower case
Either underline or italicize
Modern Classification
Problems with traditional system: focused
only on morphology (appearance)
Modern Criteria for Classification uses:
*Morphology/Anatomy
*Development
*DNA Comparison- DNA sequences
*Evolutionary descent
Dichotomous Key
Tool for classifying unknown organisms
Uses 2 sets of descriptors, known as
couplets
Steps:
Always start at #1
 Follow couplets based on organism’s
characteristics

1) Peacock Flounder
2) Spotted Goat Fish
3) Glassy Sweeper
4) Squirrel Fish
5) Spotted Eagle Ray
6) Band Tail Puffer
7) Spotted Moray Eel
8) Glass Eyed Snapper
9) Trumpet Fish
Rajidae
skates
Alopiidae
Thresher Shark
Pristophoridea
Saw Shark
Carcharhinidae
Tiger Sharks
Scyliorhinidae
Cat Shark
Rhincodontidae
Whale Shark
Isuridae
Mackerel Sharks
Squalidae
Dogfish Sharks
Dasyatidae
Stingrays
Scapanorhynchidae
Goblin shark
Pseudotriakidae
False Cat sharks
Hexanchidae
cow sharks
Sphyrnidae
Hammerhead shark
Mobulidae
Manta Ray
Evolutionary Classification
Cladistics: the science of grouping
organisms based on evolutionary descent,
not just morphology.
Cladogram: a diagram that shows
evolutionary relationships among organisms.
Derived character: characteristic that appears
in recent parts of a lineage, but not in the
older members. Used to build cladograms.
Cladogram
www.biologycorner.com/cladogram/cladogram_2.htm#
Cladogram Practice
Examine the sample cladogram, each
letter on the diagram points to a derived
character, or something different (or
newer) than what was seen in previous
groups. Match the letter to its character.
Note: this cladogram was created for
simplicity and understanding, it does not
represent the established phylogeny for
insects and their relatives.
To make a cladogram, you must first look at the
animals you are studying and establish the
characteristics that they share and ones that are
unique o each group. For the animals on the table,
indicate whether the characteristic is present or not.