1. Classification
Organizing Life

2. Scientists estimate that between 5 & 30 million species of organisms live on our planet, although fewer than 2 million have been identified and named. In order to simplify the study of these organisms, biologists have organized living things into related groups.

3. Some Key Vocabulary
Classification  grouping of objects or information based on similarities
Taxonomy  the branch of Biology concerned with the grouping and naming of organisms

4. WHY CLASSIFY?
Taxonomists organize living things into groups using a set of characteristics or criteria that shows similarities or differences
Logic
Order
Taxonomy is a useful tool
Pine trees have a resin used as a disinfectant; other evergreens might also have useful substances.
(Medicine) similar plants might contain similar chemical substances.
It is used in agriculture, forestry, & medicine
It is important to the economy

5. HOW DO WE CLASSIFY? Dichotomous key
A set of paired statements that can be used to identify organisms
Organisms can be identified and relationships can be determined by ancestors, development, biochemistry, or behavior.

6. And now….a history lesson…

7. Aristotle’s system He developed the first method of classification
His system had two major groups of organisms – plants and animals
He grouped things according to where they were commonly found.
Ex: Bats & Birds are related because they both live in the air.
Problems with Aristotle’s system
Greek Philosopher (384BC – 322BC)
Birds, bats, & flying insects would be grouped together even though they have little in common besides the ability to fly.
Some animals live both on land and in the water.
It did not show natural relationships among organisms

8. Linnaeus’ system Developed a system that’s still used today
He grouped organisms based on shared physical characteristics.
Example #1:
Flowering plants were grouped according to the number and similarities of reproductive structures
Example #2:
Bats – fly, hair, feed milk to young
Birds – fly
(Bats are grouped with mammals not birds)

9. BINOMIAL NOMENCLATURE
Linnaeus’ system
He developed a two-word system called:
BINOMIAL NOMENCLATURE
Capitalized 1st word = genus name (group of closely related species)
Lower case 2nd word = species name (description of organism)
Examples
Grizzly Bear  Ursus arctos
Polar Bear  Ursus maritimus

10. Used to name the organism
TAXONOMIC CATEGORIES
Organisms are grouped into a series of categories called TAXA:
DOMAIN – most inclusive, groupings of kingdoms
KINGDOM – group of related phyla
PHYLUM – group of related classes
CLASS – group of related orders
ORDER – group of related families
FAMILY – group of closely related genera
GENUS
Used to name the organism }
SPECIES

11. TAXONOMIC CATEGORIES Grizzly bear Black bear Giant panda Red fox
Abert squirrel
Coral snake
Sea star
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos

12. THE THREE DOMAINS BACTERIA ARCHAEA EUKARYA
Viruses are left our of the kingdoms because they cannot live on their own, they are not considered cells and thus are not considered to be living.

13. THE SIX KINGDOMS EUBACTERIA ARCHAEBACTERIA PROTISTS FUNGI PLANTS
Viruses are left our of the kingdoms because they cannot live on their own, they are not considered cells and thus are not considered to be living.
ANIMALS

14. CONCEPT MAP FOR LIVING THINGS
are characterized by
such as
and differing
which place them in
which coincides with
which is subdivided into
Living Things
Kingdom Eubacteria
Kingdom Archaebacteria
Eukaryotic cells
Prokaryotic cells
Important characteristics
Cell wall structures
Domain Eukarya
Domain Bacteria
Domain Archaea
Kingdom Plantae
Kingdom Protista
Kingdom Fungi
Kingdom Animalia

15. Describe Modern Evolutionary classification
This classification system grouped organisms based on their phylogeny not just physical similarities.
Phylogeny – evolutionary history of a species.

16. Evolutionary histories are based on the following:
Structural Similarities
Breeding Behavior
Geographical Distribution
Chromosome Comparisons
Biochemistry

17. Structural Similarities
Shared physical structures
-different types of cats
-dandelion, sunflower

20. Breeding Behavior
How animals attract the opposite sex.
-frogs croak…birds chirp…baboons have colorful backsides

22. Geographical Distribution
Location of species

23. Chromosome comparisons
Chromosomes nearly identical in structure
-cauliflower, cabbage, kale
-Chimpanzees, humans, gorillas

25. Biochemistry Similar DNA sequences Red panda and raccoons
Giant pandas and bears

28. Quiz
Why was the use of Linnaeus’s system better than Aristotle’s system?
Define phylogeny.
Name the taxonomic rankings in order from smallest to largest.
Name two things that are considered when using Evolutionary classification.
Which system is used to name organisms?