Transcript Classification

Classification
5.5.1 Outline the binomial system of nomenclature
5.5.2 List seven levels in the hierarchy of taxa
Why Classify?
 2.5 million species identified so far
 Not even close to complete inventory
 Need a system to organize species
What makes a good system?
 Assign a universally accepted name to
each organism so every scientist knows
exactly what is being discussed.
 Grouping should have good biological
reason so that researchers can expect a
group to share important
characteristics.
Biological Classification
 By 18th century needed universal
naming system that did away with
common names
 Solved language issues
 Meant that same name was not being
used for different organisms
Early Scientific Names
 Described physical characteristics of
organism
 Could be 20 words long
 For example:
“Oak with deeply divided leaves with no
hairs on the underside, and no teeth
around their edges.”
Binomial Nomenclature
 Carolus von Linnaeus
 Two-word naming system
 Genus
 Noun, Capitalized,
Underlined or Italicized
 Species
 Descriptive, Lower Case,
Underlined or Italicized
Carolus von Linnaeus
(1707-1778)
Swedish scientist who laid the
foundation for modern taxonomy
Binomial Nomenclature
 Example:
Acer rubrum is the scientific name for a
red maple
-- Acer is the genus name and all maple
trees carry this name
-- rubrum means “red” and is the species
name
"Formal" scientific names should have a
third part, the authority.
The authority is not italicized or
underlined.
The authority is written as an abbreviation
of the last name of the person responsible
for naming the organism.
Authority continued
Since Carolus Linnaeus was the first person
to name many plants, the L. for Linnaeus
is very common in plant scientific names.
 An example is Quercus alba L.
Kingdoms and Domains
The three-domain system
Bacteria
Archaea
Eukarya
The six-kingdom system
Bacteria
Archaea
Protista
Plantae
Fungi
Animalia
Plantae
Fungi
Animalia
The traditional five-kingdom system
Monera
Protista
Hierarchical Classification
 Taxonomic categories
 Kingdom
King
 Phylum
Philip
 Class
Came
 Order
Over
 Family
For
 Genus
Great
 Species
Spaghetti
Phylum / Division
 Division used in plants, fungi and
bacteria kingdoms
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
History
 Aristotle 388-322 BC
Plants/Animals
 Haeckel (1866)
Plants/Animals/Protists
 Whittaker (1969)
Fungi/Plants/Animals/Protists/Monerans
 Woese,Kandler, Wheelis (1990)
Domain system
(Archea, Bacteria, Eucarya)
Arisotle’s system
 Historia Animalium
 Plant classification lost
 Heirarchy – humans at top but species
unchanging not an evolutionary tree
 System persisted with little change until
16th century
Three Kingdoms
 Plants
 Animals
 Minerals
1735 1st edition
1758 10th edition
Classification of Humans