CLASSIFICATION
Chapter 15 section 4
 Scientists classify organisms into
a hierarchy of groups based on
evolutionary relationships
 Organisms are put into groups
based on similarities
 The more similar the organisms,
the more recent the common
ancestor
 Help show evolutionary
relationships
I.
Naming organisms
Genus + species name
II.
Taxonomic hierarchy
Broad
Similarities
Domain
Kingdom
specific
similarities
example:
Phylum
Class
Order
Family
Genus
Species
III. Phylogenetic trees and
cladistics
 Construction of evolutionary
trees based on shared
characteristics
 Tree is called a cladogram
Ex: vertebrates
IV. Tools scientists use to
construct these cladograms
 Physical characteristics
 Molecular biology: compare
amino acid and DNA sequences
V. The Domains and Kingdoms of
life
A. History
 Linnaeus
2 kingdoms: plants and animals
 Wittaker (1969)
5 kingdoms:
Monera (bacteria), Protists,
Fungi, Plants, Animals
 Waese (1996)
o Added a level above
kingdom = domain
o 6 kingdoms
B. The Domains and Their
Kingdoms
 Domain = Archaea
o Kingdom archebacteria
 Domain = Bacteria
o Kingdom = bacteria
 Domain = eukarya
o Kingdoms = Protists, Fungi,
Plants, Animals
B. The recent change
Before 1996:
Bacteria
eukaryotes
archebacteria
Universal ancestor
After 1996:
Bacteria
eukarya
archea
Universal ancestor
Why the switch?
Biochemical analysis revealed
that archebacteria more closely
resemble eukaryotes than they do
other bacteria
biochemical archaea bacteria eukarya
feature
introns
yes
no
yes
cell wall of
no
yes
no
peptidoglycan
VI. Characteristics of the Kingdoms
A. Kingdom Archebacteria
 Prokaryotic
 Unicellular
 Many live in extreme
environments
 More similar to eukaryotes
than to other bacteria
 Cell wall NOT peptidoglycan
 Have introns in genes
B. Kingdom Bacteria
 Prokaryotic
 Unicellular
 Cell wall of peptidoglycan
 No introns in genes
 Less similar to eukaryotes
 Some are heterotrophs some
are autotrophs
C. Kingdom Protista
 Eukaryotic
 Most are unicellular
 Some are heterotrophs some
are autotrophs
 As of 2012 this kingdom has
been broken into 9 new
kingdoms
D. Kingdom Fungi
 Eukaryotic
 Most are multicelled
 Cell wall of chitin
 All are heterotrophic
 All absorb food
E. Kingdom Plantae
 Eukaryotic
 Multicellular
 Autotrophic
 Cell wall of cellulose
 Reproduce sexually with egg
and sperm
F. Kingdom Animalia
 Eukaryotic
 Multicelled
 Heterotrophic
 Motile
 No cell walls
 Reproduce sexually with egg
and sperm