introduction to biological classification

1. Diversity of Life:
Introduction to
Biological
Classification
By Deanne Erdmann, MS
BioEd Online

2. Why Do We Classify Organisms?
 Biologists group organisms to represent
similarities and proposed relationships.
 Classification systems change with
expanding knowledge about new and
well-known organisms.
Tacitus bellus
BioEd Online

3. Leucaena leucocephala
Lead tree
Classification
 Binomial Nomenclature
 Two part name (Genus, species)
 Hierarchical Classification
 Seven Taxonomic Catagroies
 Systematics
 Study of the evolution of biological diversity
BioEd Online

4. Carolus von Linnaeus
(1707-1778)
Swedish scientist who laid
the foundation for modern
taxonomy
Binomial Nomenclature
 Carolus von Linnaeus
 Two-word naming system
 Genus
 Noun, Capitalized,
Underlined or Italicized
 Species
 Descriptive, Lower Case,
Underlined or Italicized
BioEd Online

5. Hierarchical Classification
 Taxonomic categories
 Kingdom King
 Phylum Philip
 Class Came
 Order Over
 Family For
 Genus Green
 Species Soup
BioEd Online

6. Kingdoms and Domains
Bacteria Archaea Eukarya
Bacteria Archaea Protista Plantae Fungi Animalia
Monera Protista Plantae Fungi Animalia
The three-domain system
The six-kingdom system
The traditional five-kingdom system
BioEd Online

7. Systematics:
Evolutionary Classification of Organisms
 Systematics is the study of the evolution of biological
diversity, and combines data from the following areas.
 Fossil record
 Comparative homologies
 Cladistics
 Comparative sequencing of DNA/RNA among
organisms
 Molecular clocks
BioEd Online

8. Taxonomic Diagrams
Mammals Turtles Lizards and
Snakes
Crocodiles Birds Mammals Turtles Lizards and
Snakes
Crocodiles Birds
Cladogram
Phylogenetic
Tree
BioEd Online

9. Dichotomous Keys Identify Organisms
 Dichotomous keys versus evolutionary classification
 Dichotomous keys contain pairs of contrasting
descriptions.
 After each description, the key directs the user to
another pair of descriptions or identifies the organism.
Example:
1. a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
2. a) Are margins of the leaf jagged? Go to 4
b) Are margins of the leaf smooth? Go to 5
BioEd Online

10. Thank You
 This concludes a brief review of biological
classification.
 You may find additional information on this section of
in the expanded content talks and in the notes below
each slide in the slide library.
BioEd Online