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

Carl 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 NamesScientific 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 show derived characteristics

• 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

• Broadest of all taxa• Grouped into

3 domains:1. Bacteria :

• Eubacteria

2. Archea:

• 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 eukaryotesb. Photosyntheticc. Autotrophs

*(make own food)*Examples: plants

6. Kingdom Animalia:a. Multicellularb. Consumers that eat & digest other organisms (heterotrophs)c. May be herbivores, carnivores & omnivores*Examples: Animals

Complete Classification of Humans

1. Kingdom: (Animalia)

2. Phylum: (Chordata)• Dorsal nerve cord-

cartilage• Vertebrae

3. Subphylum: (Vertebrata)

4. Class: (Mammalia)

5. Order: (Primates)

6. Family: (Hominid)

7. Genus: (Homo)

8. Species: (sapiens)