Taxonomy is the field of biology that deals
with the organizing living things into a
hierarchy or category that show artificial/
natural and evolutionary relationships.
Systematics or MODERN TAXONOMY
 20 M unknown species*
 2.5 M identified
 System of Biological Classification
 Important features:


Universally accepted
Placement of organisms into groups has real biological meaning
Taxonomy or Systematics involves three
procedures namely classification,
identification and nomenclature.
 Identification
 recognize organism based on…
 establishment of the organisms traits
 Classification
 assigning arbitrary categories
 based on its biological relatedness
 Nomenclature
 Practice of naming based on the rules of ICZN and ICBN
 study of the theory,
practice and rules of
classification
 naming, description and
classification
 study of the diversity of
organisms and their
natural relationships
 encompasses questions
of diversity and disparity
Who is the Father of Taxonomy?
-Invented the sexual system
- Published Species Plantarum and
Systema Naturae
“ no man has ever transformed science in a way that I have”
 16Th century
 start of scientific naming
 polynomial LATIN names
 Why Latin?
 scholarship language
 dead language
 Problems with Polynomial names
 Differs from every scientist
 organisms of the same genus (conflict)
What is the universally accepted system of
naming organisms?
-2 part name
-Genus and Species
-Latin
-Can be written in italicized or
underlined format
Solanum caule inermi
herbaceo foliis pinnatis
incisis
“ Solanum with smooth
stem which is herbaceous
and has incised pinnate
leaves”
TOMATO: Lycopersicon
esculentum
 system of naming organisms using a two-part
Latinized (or scientific) name
 also known as the Linnaean system
 first part: generic name (genus), second: specific or
trivial name (species).
 Latin name is usually printed in italics, starting with a
capital letter
Scientifc name:
Ursus maritimus Phipps
Ursus maritimus Phipps
Ursus Maritimus Phipps
Ursus maritimus Phipps
ursus maritimus Phipps
Ursus maritimus Phipps
Ursus maritimus Phipps
How many CATEGORIES (general categories)
are there in the levels of classification of
organisms?
Kingdom, Phylum, Class, Order,
Family, Genus and Species.
 structural similarities
 hierarchical
 Category- each level of classification
 Taxa/ taxon- specific group in each category
Division/Phylum
Class
Order
Family
Genus
Genus
Species
LINNAEAN
CLASSIFICATION SYSTEM
Kingdom
How did Linnaeus view species???
described all the things that had been put to earth by the
creator
Who defined the BIOLOGICAL SPECIES CONCEPT: A
gorup of similar individuals that can usually
interbreed among themselves and produce a fertile
offspring.
Charles Darwin
Carl Von Linne
Ernst Mayr
Steve Irwin
None of the above
CLASSFICATION is BASED on:
Structural
Rituals, habit, diet, way of
living
Biochemical
cells
Cytological
body parts
Embryological
Protein, DNA
Behavioral
Early developmental stages
TAXONOMY is also BASED on…
 Evolutionary lineages/patterns
 Homologous vs. analogous structures
 Fossil records
Popular Methods of
Classification
Evolutionary
Systematics
Ernst Mayr (1904) and
George G. Simpson
(1961)
 reflected
relatedness as well
as morphological
disparity (overall
similarity)
Phenetic Systematics
(1960’s)
overall similarity among
organism
grouped by a
mathematical analysis
results fail to reflect
evolutionary relationships
James Rohlf, Robert Sokal,
and Peter Sneath
delimits variation within
and between populations
Cladistic Systematics
Willi Hennig
standard method of
phylogenetic inference
Objectives:
determine
the
evolutionary histories
express it in
phylogenetic trees
After knowing the overall
similarities
concentrate
on only
certain characters-those
that provide evolutionary
information
based on the assumption that two new
species are formed by splitting from a
common ancestor
Which BIOLOGICAL CLASSIFICATION
SCHEMES is widely accepted today?
3 Domain system
2 Kingdom classification
4 Kingdom classification
5 Kingdom classification
6 Kingdom classification
3 DOMAIN SCHEME
2 KINGDOM SCHEME
PLANTAE
ANIMALIA
ANIMALIA
PLANTAE
FUNGI
MONERA
ANIMALIA
PLANTAE
MONERA
FUNGI
PROTISTA
MONERA
ANIMALIA
PLANTAE
MONERA
ARCHAEBACTERIA
PROTISTA
EUBACTERIA
FUNGI
MONERA