Classification/Taxonomy

1
Classification/Taxonomy

• Chapter 18

2
Why Classify?

• To study the diversity of life, biologists use a
• classification system to name organisms
• group them in a logical manner.

3
Taxonomy

• Defined
• Discipline of classifying organisms and assigning
  each organism a universally accepted name.
• In other words, naming things.

4
Why common names dont work

• Common names vary among languages.
• Example
• United Kingdom Buzzard refers to a hawk
• United States Buzzard refers to a vulture

Red-tailed Hawk
Honey Buzzard
Turkey Vulture
5
Early Taxonomists

• 2000 years ago, Aristotle (384 BC-322 BC) was the
  first taxonomist
• Aristotle divided organisms into plants animals
• He subdivided them by their habitat ---land, sea,
  or air dwellers

6
Carolus Linnaeus

• (1707 1778)
• Classified organisms by their structure
• Created the system of naming we use today.
• His classification system includes 7 levels.
• In taxonomy, a group or level of organization is
  called a taxonomic category or taxon.

7
Binomial Nomenclature

• Bi means 2
• nomial means naming
• Nomenclature means the system of
• Defined
• In binomial nomenclature, each species is
  assigned a two-part scientific name.

8
Example of Binomial Nomenclature

• Polar Bear is Ursus maritimus
• Ursus genus
• Ursus contains 5 other kinds of
  bears
• maritimus species
• The Latin word, maritimus,
  refers to the sea.
• Polar bears often live on pack ice that floats
  in the sea.

9
Definitions to know

• Genus is a group of closely related species
• Species Group of similar organisms that can
  breed and produce fertile offspring

10

• Kingdom Largest taxonomic group,
• consisting of closely related
• phyla.
• Phylum Group of closely related classes
• Class Group of similar orders
• Order Group of similar families
• Family Group of genera that share many
  characteristics

11
Here We GoPolar Bear

• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Carnivora
• Family Ursidae
• Genus Ursus
• Species maritimus
• What do these mean?...lets see

12
What they mean

• Species maritimus (lives in marine environment)
• Genus Ursus (kind of bear)
• Family Ursidae (larger category of bears)
• Order Carnivora (meat-eating animals)
• Class Mammalia (warm-blooded, hair, milk)
• Phylum Chordata (vertebrates)
• Kingdom Animalia (there are 6 kingdoms)

13
How to remember

• King Phillip Came Over For Green Salad
• Kingdom Phylum Class Order Family Genus Species

14
Rules of the Game

• Uniqueness Every name has to be unique.
• Universality Zoologists have adopted, by
  international agreement, a single language to be
  used on a worldwide basis. All animals are given
  a generic (common name) and specific name in
  Latin (scientific name).
• These names are in italics or are underlined
• (i.e. Homo sapiens).

15
Phylum Chordata
Class Mammalia
Order Carnivora
Family Ursidae
Genus Ursus
Species maritimus
16
Genus species

• If these three species belong to the same genus,
  they are descended from a common ancestor.

Felis domestica
domestica
Domestic Cat
Felis
Felis leo
leo
Lion
Felis margarita
margarita
Sand cat
17
Which TWO are more closely related?
18
A Problem with Traditional Classification

• Traditional classification systems relied on
• body structure comparisons only
• Due to convergent evolution, organisms that
• are quite different from each other evolve
• similar body structures.
• Convergent Evolution Process by which unrelated
  organisms independently evolve similarities when
  adapting to similar environments.

19
A Problem with Traditional Classification

• Example The Crab, The barnacle, The limpet
• The barnacle and the limpet have similarly shaped
  shells look alike
• The crab has a very different body form
• Based on anatomy, the barnacle limpet could be
  classified together and the crab in a different
  group.

20
Related
This incorrect because crabs and barnacles are
actually related
21
Crustaceans
Gastropods
Molted Exoskeleton
Even though they do not look a like, crabs
barnacles are actually related
Segmentation
Free swimming Larva
22
Evolutionary Classification

• Biologists now group organisms into categories
  that represent lines of evolutionary descent, not
  just physical similarities
• Evolutionary Classification Is the strategy of
  grouping organisms together based on their
  evolutionary history.

23
Classification Using Cladograms

• Cladogram A diagram that shows the evolutionary
  relationships among a group of organisms.

24
Crustaceans
Gastropods
Molted Exoskeleton
Using Cladograms, you can see that crabs and
barnacles share similar characteristics because
they both molt are segmented
Segmentation
Free swimming Larva
25
Crustaceans
Gastropods
Molted Exoskeleton
You can also see that ALL have a free swimming
larva stage
Segmentation
Free swimming Larva
26
Classification History

• 1700s Plantae
  Animalia
• 1800s Protista
  Plantae Animalia
• 1950s Monera
  Protista Fungi Plantae Animalia
• 1990s Eubacteria Archaebacteria Protista
  Fungi Plantae Animalia

27
The Three-Domain System

• Recently, as evidence about microorganisms
  continue to accumulate, biologists came to
  realize that the Kingdom Monera were composed of
  2 distinct groups.
• The 6-Kingdom system of classification includes
  kingdoms
• 1. Eubacteria 2. Archaebacteria 3.
  Protista
• 4. Fungi 5. Plantae
  6. Animalia

28
6 Kingdoms

• Eubacteria Archaebacteria Protista
  Fungi Plantae Animalia

Prokaryote
Prokaryote
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Autotroph or heterotroph
Autotroph or heterotroph
Autotroph/ heterotroph
Heterotroph
Heterotroph
Autotroph
Includes Algae Dont belong in other euk
No cell wall No chloroplasts Multicellular
Ancient Bacteria
Release enzymes to digest food
Most common bacteria
Cell walls Chloroplasts
Live in very hot places
E. ecoli
Paramecium
Fern frod
H. coccinea
Homo sapiens
Pyrococcus furiosus
29
Where do viruses go?

• Viruses Are particles of nucleic acid, protein,
  and in some cases lipids that can reproduce ONLY
  by infecting living cells.
• Viruses are made of a core of either DNA or RNA
  surrounded by a protein coat.

These are T4 Bacteriophage
A bacteriophage is a virus which infects bacteria
30
Where do viruses go? (continued)

• Viruses are not considered alive because they
  dont have ALL the characteristics of life.
• Example They cant reproduce independently

These are the Influenza Viruses
Influenza or "flu" is an infection of the
respiratory tract that can affect millions of
people every year.
31
The End.
32
Visuals
33
Taxonomy Video