Chapter 18
Classification
Taxonomy
– the science of classification
• Carolus Linnaeus’ system:
– Uses Latin…descriptive, universal,
“dead” language that never changes
– Uses binomial nomenclature
• Two word naming system of
Genus & species = scientific name
– Uses hierarchy of categories (taxons)
from general to specific:
Taxonomic levels
Domain
Eukarya
Kingdom
Animalia
Chordata
Phylum
Class
Mammalia
Carnivora
Order
Family
Genus
Felidae
Lynx
Species Lynx Lynx
rufus canadensis
Bobcat Lynx
Kingdom…Phylum…Class…Order…Family…
Genus species…(variety) or (breed)
Who am I?
Who am I?
Scientific Name:
Felis concolor
The Puma holds the Guinness record for
the animal with the highest number of
names. It has more than 40 names in
English.
Puma, Mountain lion, Cougar, Panther
Comparing related animals
Lynx
House cat
• Lynx canadensis, lynx
• Felis concolor, mountain
lion
Mountain
lion
• Felis domesticus, house cat
• Which two are more
related? How do you know?
Human classification:
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Hominidae
Genus
Homo
species
sapiens
Remember the 2 Cell Types?
• Prokaryotic
– Small, simple cells without
membrane-bound
organelles; i.e. bacteria
• Eukaryotic
– Large, complex cells
containing many specialized
organelles, nucleus; i.e.
plants, animals, protists &
fungi
• All living things are divided into groups
based on:
– Cell types (Prokaryotic vs. Eukaryotic)
– Cell structure (cell walls, chloroplasts?)
– Number of cells (unicellular vs. multicellular)
– Movement (motile or non-motile)
– Mode of nutrition (autotroph, heterotroph,
saprobe)
Domains
• Largest , most inclusive group
– Archaea: Prokaryotic cells
• 1 kingdom: Archaebacteria
– Bacteria: Prokaryotic cells
• 1 kingdom: Eubacteria
– Eukarya: Eukaryotic cells
• 4 kingdoms: Protista, Fungi, Plantae, Animalia
Kingdom Archaebacteria
• Most live in extreme
environments
– Most do not use oxygen to
respire (anaerobic).
– Ancestor to eukaryotes
• Unicellular
• Cell walls lack peptidoglycan
• Can be heterotrophic or
autotrophic
• Some motile, others nonmotile
• Examples: Halophiles,
methanogens.
Kingdom Eubacteria
• Unicellular
• Very strong cell
walls
(peptidoglycan)
• Autotrophic or
heterotrophic
• diverse habitat
• Some motile, other
non-motile
• Ex: streptococcus,
Escherichia coli
Kingdom Protista
• Most are unicellular, few are
multicellular
– lacks complex organ systems
• lives in moist environments
• diverse metabolism/motility
– Animal-Like
– Plant-Like (cellulose,
chloroplasts)
– Fungus-Like
• Ex: Amoeba, euglena, slime
molds
Fungi overview
• Saprobes: decomposes
matter by absorbing
materials
• Multicellular
(mushrooms) or
unicellular (yeast)
• Cell walls (chitin)
• Non-motile
Kingdom Plantae
• Multicellular
• Autotrophic:
Photosynthetic
– Cells contain
chloroplasts
• Immobile
• Cell walls
(cellulose)
• Ex: grass, rose
Kingdom Animalia
•
•
•
•
•
•
Multicellular
Mobile (at one point during their lifetime)
Lack cell walls
Diverse habitats
Heterotrophic
Ex: insects, worms,
squirrels, birds
Organism
Number
Described
Estimated number to be
Discovered
Viruses
5,000
about 500,000
Bacteria
4,000
400,000-300 million
Fungi
70,000
1-1.5 million
Protozoans
40,000
100,000-200,000
Algae
40,000
200,000-10 million
Flowering plants
250,000
300,000-500,000
Roundworms
15,000
500,000-1 million
Mollusks
70,000
200,000
Crustaceans
40,000
150,000
Spiders and mites
75,000
750,000-10 million
Insects
950,000
8-100 million
Vertebrates
45,000
50,000
Exit Ticket
Which characteristic describes these three
organisms?
A) Unicellular
B) Heterotrophic
C) Prokaryotic
D) Phototrophic
How do we identify
organisms?
Dichotomous key: system to identify
organisms and their scientific names
• A key is made up of sets of numbered
statements.
• Each set deals with a single characteristic
of an organism, such as leaf shape
(toothed or smooth edge) or number of
teeth (more than 30 or less than 30).
• It’s kind of like the game 20 questions
Phylogeny
Phylogeny: Studying the evolutionary
histories and relationships of organisms
• Cladistics: a phylogenic study that
assumes when probable groups of
organisms diverged and evolved
Allosaurus
Velociraptor
Archaeopteryx
Sinornis
Theropods
Light bones
Feathers with Flight feathers;
3-toed foot; Down
arms as long
shaft, veins,
wishbone feathers
as legs
and barbs
Cladograms
• “Family tree” that represents evolutionary
relationships (and not just physical
appearances)
CLADOGRAM
Hagfish
Fish
Lizard
Frog
Mouse
Pigeon
Chimp
Feathers
Fur &
Mammary
Glands
Lungs
Jaws
Claws
or Nails
Nutritional types
Auto(photo)
Hetero(absorb) Hetero(ingest)
Fungi
(Seaweeds)
Animalia
Multi
Uni
Protista
Eu
Pro
Bacteria
What determines evolutionary
relationship?
• Anatomy and physiology
– Common structures imply a common
ancestor.
• Breeding and behavior patterns
• Geographic distribution
• DNA and biochemistry
DNA comparisons between these plants show almost no difference.