1. Taxonomy – the branch of biology
that names and groups organisms according to their characteristics
and evolutionary history. (Holt)

2. Through taxonomy scientists classify organisms and assign each organism a universally acceptable name. (Prentice Hall)

3. Scientists Aristotle – over 2000 Plants and animals.
years ago, he developed
the first system of classification.
He divided all living
organisms into two
categories:
Plants and animals.

4. Aristotle’s Classification Scheme
Plants were divided into three
groups: herbs with soft stems,
shrubs, and trees with
a single wood stem.
Animals were divided into
land dwellers, water dwellers
and air dwellers.

5. He devised a system
of grouping organisms
into hierarchical categories.
He used structure and form
of organisms (morphology)
to help classify them.

6. Linnaeus’s Levels of Classification
Linnaeus developed a system of seven levels or “taxa” (singular = taxon).
The levels are grouped from the largest most inclusive group to the smallest most exclusive group.

7. Seven Levels of Taxonomy:
DOMAIN
1- Kingdom
2- Phylum (or Division)
3- Class
4- Order
5- Family
6- Genus
7- Species

8. Scientific Names
Linnaeus also developed a system of naming called Binomial Nomenclature in which the species name of an organism is made up of two parts: the genus name & the species identifier.
Example: Grizzly bear
(common name)
binomial nomenclature
= Ursus arctos
(usually in italics, first word capitalized.)

9. Why do scientists avoid using common names when discussing organisms?
Common names can be confusing because they may vary among languages and even among regions in a single country.
Example: A cougar
is a puma,
is a mountain lion
is a catamount
is a ghost cat

10. Pyractomena borealis (example of scientific name)
Common names: Lightning bugs
Glowworms, or Fireflies (They are not
really flies – they are beetles. Flies have one pair of wings, while other winged insects have two or four pairs of wings. When the name of an insect contains the word fly, such as dragonfly, or firefly, they are not flies.)

11. Examples of other Firefly Genera.
Lamprocera – brilliant and wax-colored Microphotus – small light Macrolampis – big light Pyrogaster – fire stomach Lampyris – glowworm Pyropyma – fire butt

13. Sometimes different species can share the same common name:
United Kingdom: Buzzard = Hawk
United States: Buzzard = Vulture

14. Other Examples: Humans = Homo sapiens Lion = Panthera leo House cat =
Felis domesticus
Domesticated dog =
Canis familiaris
Red Maple Tree =
Acer rubrum

15. Six Kingdom System: Archaebacteria = unicellular prokaryotes
(descended from & very similar to first cells)
Eubacteria = unicellular prokaryotes
(most bacteria that affect you)
Protists =
protozoans & algae
Fungi = fungi
Plantae = plants
Anamalia = animals

16. on body characteristics.
Traditional classification relied primarily
on body characteristics.
Biologists now group organisms into categories that represent lines of evolutionary descent, as well as physical characteristics.
DNA analysis is an important tool
in classification science. It
can be used to show how
closely related organisms may be.