History & Use of Biological
Classification
CLASSIFICATION & TAXONOMY
Classification: • grouping based on
similarities
Taxonomy: • Branch of Biology• The science of
classifying/grouping and naming of organisms
Aristotle’s Classification Scheme
• Greek philosopher who developed first classification system
• Divided all organisms into 2 GROUPS: 1. Non motile (plants)2. Motile (animals)
• Plants grouped by:– size (small, medium, large)
• Animals grouped by:– where they lived (air, water, land)
Binomial Nomenclature• A system for naming
organisms by structure created by Linnaeus:– Although Linneaus didn’t realize
it, by classifying organisms by structure he was also classifying them by evolutionary relationship
• Written in Latin• Includes the organisms :• Genus: CAPITALIZED (noun)
– means beginning
• Species: lowercase (adj.) Example: Homo (man) sapien
(wise/thinking)
Scientific & Common Names
Scientific Name: • genus and species name
– Iguana iguana– Felis domesticus
Common name: • Organism is commonly
called• Not used in the
scientific community– Green Iguana– Domestic Cat
The “New” Evolutionary Classification
• Categories that represent lines of evolutionary descent
• Not just physical similarities
• This new method is called: Evolutionary Classification
• Scientists classify organisms based on their Evolutionary Beginnings
Cladograms
• A diagram that shows evolutionary relationships
• Cladograms are useful tools
• Help scientists understand how one lineage branched from another in the course of evolution
Traditional Classification vs. Cladogram
TRADITIONAL CLASSIFICATION
CLADOGRAM
Appendages Conical Shells Crustaceans Gastropoda
Crab Barnacle Limpet
Physical Similarities Evolutionary Decent: Class
Molten exoskeleton
Segmentation
Free-swimming larvae
Kingdoms
• Second broadest of all taxa
• Grouped into 3 domains:1. Bacteria –
• Eubacteria
2. Archae-
• Archeabacteria
3. Eukarya:
• Protista, Fungi, Plantae, and Animalia
Characteristics of the 6 Kingdoms
1. Kingdom Eubacteria: a. all microscopic
prokaryotes b. almost all are unicellular c. non-motile d. commonly called bacteria
2. Kingdom Archaebacteria: a. prokaryotes b. live in extreme
environment
3. Kingdom Protista: a. eukaryotes
b. uni and multicellular
c. live in moist environments
d. most are simple, microscopic & mobile
*Examples: paramecium, amoeba, euglena &
algae
4. Kingdom Fungi: a. Eukaryotes b. Uni and
Multicellular c. Consumers that do
not move d. Decompose dead
organisms &/or waste products
*Examples: mushrooms, molds, & mildew
5. Kingdom Plantae:a. stationary, multicelluar eukaryotes
b. Photosynthetic
c. Autotrophs
*(make own food)
*Examples: plants
6. Kingdom Animalia:a. Multicellular
b. Consumers that eat & digest other organisms (heterotrophs)
c. May be herbivores, carnivores & omnivores
*Examples: Animals
Complete Classification of Humans1. Domain: (Eukarya)
2. Kingdom: (Animalia)
3. Phylum: (Chordata)• Dorsal nerve cord-cartilage• Vertebrae
4. Subphylum: (Vertebrata)5. Class:
(Mammalia)
6. Order: (Primates)7. Family:
(Hominid)8. Genus:
(Homo)9. Species: (sapien)
Quiz 2• 1. The branch of biology in which we classify
organisms is calleda. Classonomy b. taxonomy c. botany• 2. Which is NOT a domain?a. Eubacteria b. Archaebacteria c. Monera• 3. Which is the proper way to write a scientific
name?a. Homo sapien b. homo sapien c. Homo sapien• 4. A diagram that shows evolutionary relationships is
called aa. Dichotomous key b. cladogram c. taxonomy• 5. To which kingdom would amoebas & paramecium
belong?a. Fungi b. Plantae c. Protista