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……why use a scientific name?
• Why are some kinds similar and others
NOT similar?
• Question to be answered later?
• How can we make sense of (explain) this
diversity?
• How can we organize what we know
about these organisms?
Early Efforts at Naming Organisms
• The first attempts at standard scientific names often
described the physical characteristics of a species in
great detail.
• Results in long names
• Difficult to standardize the names of organisms
• Different scientists described different
characteristics.
Answer: CLASSIFY!
• Similar “types” (species) grouped together,
separated from other species.
• Then, group similar groups together, etc.
•The science of classifying organisms is
called taxonomy.
•The “father of modern taxonomy” was
Carolus Linnaeus (Carl von Linné).
Why Do We Classify Organisms?
•Biologists group organisms to
represent similarities and proposed
relationships.
• Classification systems change with
expanding knowledge about new
Tacitus bellus
and well-known organisms.
• Classification system organizes biological
knowledge.
• Classification itself is HYPOTHESIS about
relationships, similarity because of common
ancestry.
Classification
• Binomial Nomenclature
– Two part name (Genus, species)
• Hierarchical Classification
– Seven Taxonomic Catagroies
• Systematics
– Study of the evolution of biological
diversity
Leucaena leucocephala
Lead tree
Hierarchical Classification
• Taxonomic categories
–
–
–
–
–
–
–
Kingdom
Phylum
Class
Order
Family
Genus
Species
King
Philip
Came
Over
For
Green
Soup
CLASSIFICATION = Sequence of levels.
Linnaean system, from Carolus Linnaeus, 1740's
Kingdom
Phylum
Class
Order
Family
Genus
Species
King Phil called old fat George stupid.
CLASSIFICATION = Linnaean system
The 7 taxonomic categories
• Species - a group of organisms that breed with one another
and produce fertile offspring.
• Genus - a group of closely related species.
• Family - genera that share many characteristics.
• Order - is a broad taxonomic category composed of similar
families.
• Class - is composed of similar orders.
• Phylum- several different classes that share important
characteristics.
• Kingdom - largest taxonomic group, consisting of closely
related phyla
CLASSIFICATION
Whittaker’s Five Kingdoms, 1965
• Kingdom Monera
(Bacteria)
• Kingdom Protista
• Kingdom Fungi
• Kingdom Plantae
• Kingdom Animalia
•
•
•
•
Woese, 1985
Prokaryotic organisms are far more
diverse than thought previously.
Domain Eubacteria (prokaryotic “true bacteria”)
Domain Archaea (prokaryotic “archaeans”)
Domain Eukarya (eukaryotic organisms)
The three-domain system
Bacteria
Archaea
Eukarya
The six-kingdom system
Bacteria
Archaea
Protista
Plantae
Fungi
Animalia
Plantae
Fungi
Animalia
The traditional five-kingdom system
Monera
Protista
• Prokaryotic organisms are far more diverse
than thought previously.
• Domain Eubacteria (prokaryotic “true bacteria”)
–
–
–
–
–
–
Kingdom Gram-positive bacteria
Kingdom Gram-negative bacteria
Kingdom Mycoplasmas
Kingdom Rickettsias
Kingdom purple-sulfur bacteria
and more
• Domain Archaea (prokaryotic “archaeans”)
• Domain Eukarya (eukaryotic organisms)
Domain Eubacteria
• Prokaryotic organisms are far more diverse
than thought previously.
• Domain Eubacteria (prokaryotic “true bacteria”)
• Domain Archaea (prokaryotic “archaeans”)
–
–
–
–
Kingdom Thermophiles
Kingdom Halophiles
Kingdom Methanogens
Kingdom ARMANS
• (“Archeal Richmond Mine Acidophilic Nanoorganism”
Science vol 314, 22 Dec. 2006.)
• Domain Eukarya (eukaryotic organisms)
Domain Archaea
• Prokaryotic organisms are far more diverse
than thought previously.
• Domain Eubacteria (prokaryotic “true bacteria”)
• Domain Archaea (prokaryotic “archaeans”)
• Domain Eukarya (eukaryotic organisms)
–
–
–
–
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Domain Eukarya
Kingdom Protista
Amoeba
Paramecium
Water Mold
Euglena
Dinoflagellates
Giardia
Slime Mold
Green Algae
Brown Algae
Diatom
Kingdom Fungi
Kingdom Plantae
Bryophyte
(Moss)
Pteridophyte(
Fern)
Pteridophyte(
Fern)
Coniferophytes (Pine
Trees)
Angiosperm;
Dicot
Angiosperm;
Monocot
Kingdom Animalia
Key Characteristics of Kingdoms and Domains
Classification of Living Things
DOMAIN
Bacteria
Archaea
KINGDOM
Eubacteria
Archaebacteria
CELL TYPE
Prokaryote
Prokaryote
Cell walls with
peptidoglycan
Cell walls
without
peptidoglycan
CELL
STRUCTURES
NUMBER OF
CELLS
Unicellular
MODE OF
NUTRITION
Autotroph or
heterotroph
EXAMPLES
Go to
Section:
Unicellular
Autotroph or
heterotroph
Streptococcus,
Escherichia coli Methanogens,
halophiles
Eukarya
Fungi
Plantae
Animalia
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Most
unicellular;
some colonial;
some
multicellular
Most
multicellular;
some
unicellular
Protista
Autotroph or
heterotroph
Amoeba,
Paramecium,
slime molds,
giant kelp
Heterotroph
Mushrooms,
yeasts
Cell walls of
cellulose;
chloroplasts
Multicellular
Autotroph
Mosses,
ferns,
flowering
plants
No cell
walls or
chloroplasts
Multicellular
Heterotroph
Sponges,
worms,
insects,
fishes,
mammals
Section 18-3
Living Things
are characterized by
Eukaryotic cells
and differing
Important
characteristics
which place them in
Cell wall
structures
such as
Domain
Eukarya
Prokaryotic cells
which is subdivided into
which place them in
Domain
Bacteria
Domain
Archaea
which coincides with
which coincides with
Kingdom
Eubacteria
Kingdom
Archaebacteria
Go to
Section:
Kingdom
Plantae
Kingdom
Fungi
Kingdom
Protista
Kingdom
Animalia
Kingdoms
Eubacteria
Archaebacteria
Protista
Plantae
Fungi
Animalia
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Did King Phil call old fat George stupid ?
Binomial Nomenclature
• Carolus von Linnaeus
• Two-word naming system
– Genus
• Noun, Capitalized,
Underlined or Italicized
– Species
• Descriptive, Lower Case,
Underlined or Italicized
Carolus von Linnaeus
(1707-1778)
Swedish scientist who laid
the foundation for modern
taxonomy
Ursus americanus
American Black Bear
Binomial Nomenclature: “a two-name
system”
First part of name: genus first letter always
capitalized
Second part of name: species first letter
always lowercase
Entire name is underlined and italicized
Names must be submitted for acceptance by
original discoverer, and are generally Latin
or Latinized
Often Latin
names contain
clues about the
type of organism
being described.
Canis domesticus
Canis lupus
Names are generally closely related organisms are often in the
same genus, also giving clues about their names.
Some names are given for the discoverer, or the discovery
location, or even a Latinized descriptive term in English.
Systematics:
Evolutionary Classification of
Organisms
• Systematics is the study of the evolution of
biological diversity, and combines data from
the following areas.
–
–
–
–
Fossil record
Comparative homologies
Cladistics
Comparative sequencing of DNA/RNA among
organisms
– Molecular clocks
Taxonomic Diagrams
Mammals
Turtles
Phylogenetic
Tree
Lizards and
Snakes
Crocodiles
Birds
Mammals
Turtles
Lizards and
Snakes
Crocodiles
Cladogram
Birds
A phylogenetic tree is a family tree
that shows a hypothesis about the
evolutionary relationships thought to
exist among groups of organisms. It
does not show the actual evolutionary
history of organisms.
Why a hypothesis?
Phylogenetic trees are usually based on a
combination of these lines of evidence:
Fossil record
Morphology
Embryological patterns of
development
Chromosomes and DNA
Taxa show unique combinations of characteristics.
For example, birds have feathers, beaks, and wings, and lay
eggs, while mammals have hair, teeth, and give live birth.
Cladistics - is a relatively new
system of phylogenetics
classification that uses shared
derived characters to establish
evolutionary relationships. A
derived character is a feature that
apparently evolved only within the
group under consideration.
Diagrams called cladograms are used to represent the phylogeny of
organisms.
A phylogenetic tree based on a cladistic analysis
is called a cladogram.
What derived character is shared by all the
animals on the cladogram on the next slide?
There are three basic assumptions
in cladistics:
1.Organisms within a group are
descended from a common
ancestor.
2.There is a bifurcating pattern of
cladogenesis.
3.Change in characteristics
occurs in lineages over time.
Cats are more similar to dogs than they are
to frogs, because they share a more recent
common ancestor with dogs
Traditional Classification Versus Cladogram
Appendages
Crab
Conical Shells
Barnacle
Limpet
Crustaceans
Crab
Gastropod
Barnacle
Limpet
Molted
exoskeleton
Segmentation
Tiny free-swimming larva
TRADITIONAL
CLASSIFICATION
CLADOGRAM
Mammals
Birds
Possible
evolution of
the Kingdom
Animalia
Reptiles
Amphibians
Fish
Birds
Reptile
Mammals
Feathers
Amphibian
Fish
Fur
Endothermic
Amniotic Egg
Four Limbs
Vertebrae
Modern Evolutionary Classification
• Molecular Clocks
– Comparisons of DNA can
also be used to mark the
passage of evolutionary
time.
– A model known as a
molecular clock uses DNA
comparisons to estimate
the length of time that two
species have been evolving
independently.
• Comparison reveals more
DNA in common, the more
recent the common
ancestor
Dichotomous Keys Identify Organisms
• Dichotomous keys versus evolutionary classification
• Dichotomous keys contain pairs of contrasting
descriptions.
• After each description, the key directs the user to
another pair of descriptions or identifies the organism.
Example:
1.
2.
a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
a) Are margins of the leaf jagged? Go to 4
b) Are margins of the leaf smooth? Go to 5