1. Classification Chapter 18

2. What is Classification?
System to organize ALL living things into groups with biological meaning.
Taxonomy: The study of classification.

3. Assigning a Name
Problem: Common names can vary among languages. Common name is misleading. Descriptions are too long to be a name.
ex: Mountain Lion or Puma or Cougar
ex: Starfish, dragonfly
ex:“Oak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges.”
Solution: Latinized and Greek words are commonly used to avoid any language issues. Reduce the number of words to a two part name.

4. Carolus Linnaeus Homo sapiens
The Linnean system where each species has a 2 part (scientific) name:
BIONOMIAL NOMENCLATURE
genus
Species
(Genus is 1st word, species is 2nd)
Homo sapiens
means “wise man”
perhaps in a show of hope & optimism

5. Genus groupings Classify organisms into broader groups
Species that are closely related are grouped into the same genus
Leopard Panthera pardus
African lion Panthera leo
Tiger Panthera tigris

6. Classification System
Linnaeus’ hierarchical system:
Kingdom general
Phylum
Class
Order
Family
Genus
Species specific
Taxons
(Kings play chess on fine gold squares)

8. So…, classification sequence is now:
Kingdoms and Domains
Modern groups are six kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia
Domains – newest, largest inclusive category developed from comparing r-RNA subunits. Bacteria, Archaea, Eukarya
So…, classification sequence is now:
D, K, P, C, O, F, G, S

9. Cladogram comparing Domains

10. Bacteria & Archaebacteria
Eukaryote
Prokaryote
Classification
6 Kingdom system
Prokaryotes
No separate organelles in their cells
Bacteria
Archaebacteria
Eukaryotes
Separate organelles in their cells
Protists
Plants
Fungi
Animals
Bacteria & Archaebacteria

11. Classification of Living Things
Figure Key Characteristics of Kingdoms and Domains
Taxon Characteristics
Section 18-3
Classification of Living Things
DOMAIN
KINGDOM
CELL TYPE
CELL STRUCTURES
NUMBER OF CELLS
MODE OF NUTRITION
EXAMPLES
Bacteria
Eubacteria
Prokaryote
Cell walls with peptidoglycan
Unicellular
Autotroph or heterotroph
Streptococcus, Escherichia coli
Archaea
Archaebacteria
Prokaryote
Cell walls without peptidoglycan
Unicellular
Autotroph or heterotroph
Methanogens, halophiles
Protista
Eukaryote
Cell walls of cellulose in some; some have chloroplasts
Most unicellular; some colonial; some multicellular
Autotroph or heterotroph
Amoeba, Paramecium, slime molds, giant kelp
Fungi
Eukaryote
Cell walls of chitin
Most multicellular; some unicellular
Heterotroph
Mushrooms, yeasts
Eukarya
Plantae
Eukaryote
Cell walls of cellulose; chloroplasts
Multicellular
Autotroph
Mosses, ferns, flowering plants
Animalia
Eukaryote
No cell walls or chloroplasts
Multicellular
Heterotroph
Sponges, worms, insects, fishes, mammals

12. Organizing systems Making sense out of the differences
Eastern gray squirrel
Sciurus carolinensis

13. Organizing the world of organsims
The Tree of Life
organize creatures by structure & function
how they are built
how they live
organize them into groups of closely related creatures

14. Modern Classification
Just using appearance is not enough.
New system uses:
1. Fossils
2. Dissections/comparative anatomy
3. Molecular similarities/DNA/enzymes
4. Evolutionary similarities or developmental milestones
Ex: amniotic sac, jaws, endothermic

15. Cladistics
Classifying organisms according to the order that they diverged from a common ancestor.
Ancestral characters – found in all groups
Derived characters – found in some groups
ex: backbone is an ancestral trait found in all birds and mammals
ex: hair is a derived trait found in only mammals

16. Vertebrate Cladogram What are the Derived Traits in this cladogram?
What could the ancestral trait be?
Which organisms share the trait of claws/nails?
Which organism doesn’t have any of the traits?
Which organisms are more closely related?
Perch and pigeon
Pigeon and chimp