Taxonomy

TaxonomyI. Definition: The study of classification

A. Why group things?1. Easier to find information about an

organism2. Easier to identify an organism3. Shows evolutionary relationships

II. Historical BackgroundA. Aristotle - (350 B.C.) First scientist to

group organisms as either plants or animals

B. Carolus Linnaeus (Karl Linne 1701-1778) “Father of Modern Taxonomy”1. Grouped organisms according to their

structural similarities2. Developed a “Binomial Nomenclature”

system for identifying every organism

Binomial = two word

Nomenclature = naming system

III. Binomial Nomenclature RulesA. Names are in Latin

Why?B. First name is the Genus, the second name

is the speciesC. Genus is Capitalized and species is not. D. Both names are either italicized or

underlinede.g. Canis familiarus and Homo

sapien

IV. Modern TaxonomyA. We still look at structural similarities,

but we also look at:1. Homologous structures - suggests

common ancestor

2. Developmental stages - from embryo to adult; the more similar the stages, the closer they are taxonomically

3. DNA Evidence – shows how closely species are related to each other and their taxonomic relationship

What is the closest terrestrial relative of the whale?

V. Classification Categories (taxa)

A. Different levels from the most general characteristics to more specific characteristics

B. Eight levels of taxonomy are:

Domain

Eukarya Animal

ia

Mammalia Prima

ta Homideae

Chordata

Homosapien

Kingdom Phylum

Family

Species

Class

Order

Genus

VI. Three Domains (developed in 1990)A. Archaea- Kingdom ArchaebacteriaB. Bacteria- Kingdom EubacteriaC. Eukarya- Kingdoms Protista, Fungi,

Plantae and AnimaliaVII. Six Kingdoms

A. Kingdom Archaebacteria (archae =“ancient”)

1. Prokaroytes, no nucleus, unicellular, autotroph or heterotroph

2. Ex: Extremophiles (bacteria that live in extreme places)

B. Kingdom Eubacteria1. Prokaroytes, no nucleus, unicellular,

autotroph or heterotroph2. Ex: Streptococcus and E. coli,

(“germs”)

C. Kingdom Protista1. Simple, many are unicellular, no specialization of tissues

Protozoans Alga

e

D. Kingdom Fungi1. Multicellular organisms that have a

cell wall and absorb food through the cell wall.

2. Ex: mushrooms, molds and yeast

E. Kingdom Plantae1. Multicellular organisms, contain chlorophyll,

have organs and tissues, autotrophs

F. Kingdom Animalia1. Multicellular organisms, heterotrophs, have

organs and tissues

Classification Movie