TAXONOMY & SYSTEMATICS
PRESENTED BY: DR EBE MOEMA
OFFICE: 304
NSB BUILDING
2023
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INTRODUCTION
Terminology
Taxonomy
The
science
of
naming/classifying
living
things
logical
groups
into
of
species.
the
science
naming
Systematics
of
and
organizing organisms
based on common
ancestry
evolutionary
relatedness).
(=
Terminology…..
INTRODUCTION
Species
any living things
that can act or
function
independently.
one
group
of
genetically distinct,
interbreeding
organisms/
Any
related
living
organisms that can
freely interbreed
without
complications.
Organisms
Introduction cont……
Classify these
organisms into either
plant or animal species.
A
B
C
D
E
F
Plants
Animals
C
Importance of Classification:
It makes the study
of such a wide
variety
of
organisms easy.
It helps us
understand the
interrelationship
among different
groups of
organisms.
Various fields of applied
biology
such
as
agriculture,
public
health
and
environmental biology
depend on classification
of
pests,
disease
vectors, pathogens and
components
of
an
ecosystem.
Biodiversity
This
The
living
(organisms)
have
adapted to
the
environment
to
which
they live.
includes all
the different plants,
animals,
and
microorganisms; the
genes they contain;
and the ecosystems
they form on land
and in water.
Biological
diversity
(biodiversity)
is
constantly changing. It is
increased by new genetic
variation and reduced by
extinction and habitat
degradation.
-8.7
Diversity
of life –
variety of life on
earth.
million
(new
estimates)
living
animals named = 14%
of all animals that have
lived on earth and 86%
is yet to be discovered.

Aristotle to Linneaeus, Systema Naturae:
Linneaeus
(Swedish Botanist)
–
created
a
classification
system based on
similarities
and
differences among
organisms
that
separate them into
categories.
Published1758
Linneaeus (Swedish Botanist)
Aristotle
(Greek
Philosopher)
–
devised the first
classification
system with just
two
kingdoms,
Plants
and
Animals;
The system is
still used even
to
date,
to
formally
name
and
describe
species.

Aristotle to Linneaeus, Systema Naturae:
Linneaeus (Swedish Botanist)
A
generic
name
(name of genus):
which
it
shares
with other closely
related organisms
which have features
similar
enough to place
them in the same
group.
A
specific
name
(name of species):
which distinguishes
the organism from all
other
species/
describes the specific
animal.
No
other
organism can have
the
same
combination of genus
and species.
He
devised
a
binomial system
of nomenclature
(two-word naming
system) in which
an organism is
given two names:
The
scientific
names derived by
using the system
of nomenclature is
followed all over
the world as they
are guided by a set
of rules stated in
the International
Code
of
Nomenclature.
Major Taxonomic Levels (Hierarchical system):
Note: There are many sub-taxonomic levels of the seven main
taxonomic levels, such as Subphylum, Subclass, Infraclass,
and so on. You may see many of these other sublevel taxa
listed in the taxonomic tree of an organism.
•
The classification levels become more specific towards the
bottom. Many organisms belong to the same kingdom, fewer
belong to the same phylum, and so on, with species being
the most specific classification.
Common Name:
Human
Chimpanzee
Nine-Banded Armadillo
Kingdom:
Animalia
Animalia
Animalia
Phylum:
Chordata
Chordata
Chordata
Class:
Mammalia
Mammalia
Mammalia
Order:
Primata
Primata
Cingulata
Family:
Hominidae
Pongidae
Dasypodidae
Genus:
Homo
Pan
Dasypus
Species:
sapiens
troglodytes
novemcinctus
Homo spp
Common Name:
Modern Human
Handy Man
Java Man
Kingdom:
Animalia
Animalia
Animalia
Phylum:
Chordata
Chordata
Chordata
Class:
Mammalia
Mammalia
Mammalia
Order:
Primata
Primata
Primata
Family:
Hominidae
Hominidae
Hominidae
Genus:
Homo
Homo
Homo
Species:
sapiens
habilis
ergaster/erectus
INTRO. CONT…
•
The most important characteristics used
differentiate zoological taxa are the following:
1.
Homology
to
(similar characteristics in two animals that are a product
of descent from a common ancestor rather than a product of a similar
environment) and Analogy (equivalence in biological function
between body parts or organs that have appeared independently in
different animals).
Analogy
INTRO. CONT…
2. Symmetry
3.
(the property of being the same or corresponding on
both sides of a central dividing line).
Metamerism (Segmental repetition of homologous body parts;
metameres; metasomes)
4. Internal body cavity.
5. Number of tissue layers.
Symmetry
metamerism
Int. body cavity + number
of tissue layers
INTRO. CONT…
• Vernacular
(local) names not
scientifically acceptable!
• Species name = two words – binomial
nomenclature
(international).
e.g.
Homo sapiens or Homo sapiens.
Summary
VIRUSES:
THREE DOMAINS:
DOMAIN: ARCHAEA
DOMAIN: BACTERIA
PROKARYOTES
DOMAIN EUKARYA
EUKARYOTES
CHAPTER 2:
DIFFERENT
KINGDOMS
CHAPTER 2: SUMMARY OF
DIFFERENT KINGDOMS
AKARYOTAE (viruses)
• The origin is not entirely clear;
• Fragments of DNA or RNA
• No fossil evidence – molecular techniques have been
used to hypothesize how viruses arose.
• Unable to grow and reproduce outside the host cells
• Not the first forms of life
• Diseases – influenza, mumps, polio, AIDS, rabies, etc.
DOMAIN:
ARCHAEA
• One of the two domains of the kingdom Prokaryotae, the second one is
Bacteria.
• These two domains are thought to have dominated the earth about four
billion years ago.
• The first-studied archaeans were found in extreme habitats such as salt
lakes, hot springs, and hydrothermal vents on the ocean floor, hence
they were referred to as extreme lovers (extremophiles).
• Lately, these prokaryotes have been found in normal environments.
• There’s about 300 living species of archaeans to date and these include
chemoautotrophs and chemoheterotrophs, some of which have been
identified
as
possible
human
pathogens
associated
infections. Archaeans lack a nucleus and chromosomes.
with
tooth
DOMAIN: BACTERIA
KINGDOM: PROKARYOTAE
•
First forms of life – 3 billion years ago – 1
and half to two billion years floating mats
•
No nucleus or other organelles
•
Contain DNA – not as chromosomes
•
Majority harmful - cholera, diptheria and
tetanus; some extremely useful to man.
•
Bacilli, cocci, spirilli.
Spirilli (Spiral-shaped) – Treponema pallidium
Cocci (Spherical-Shaped) - Streptococcus
Bacilli (Rod-shaped) - Salmonella
Domain: Eukarya
EUKARYOTES
• DNA in the form of chromosomes;
• True nucleus + organelles;
• Divided into different Kingdoms:
Kingdom:
ALGAE (Microbiology/
Botany)
• Aquatic
• Chloroplasts (green, red & brown)
• Unicellular - colonial
THE DIFFERENT KINGDOMS
CONT…
Kingdom:
PROTISTA
Subkingdom:
Protozoa
Kingdom:
(Zoology)
FUNGI
(Microbiology)
• Land organisms but depend on
moisture
• No chlorophyll – secrete enzymes
THE DIFFERENT KINGDOMS
CONT…
Kingdom:
PLANTAE
(Botany)
Kingdom:
ANIMALIA
(Zoology)
THE DIFFERENT KINGDOMS CONT…
EUKARYOTES
• Nucleus surrounded by a membrane
• DNA in the form of chromosomes
• Contain organelles- autotrophs
- herbivores
heterotrophs
• Mitosis
- carnivores
THE DIFFERENT KINGDOMS
CONT…
ALGAE
• Aquatic, freshwater or marine
• Contain chloroplasts – photosynthesis –
autotrophic
• Red, green & brown algae
• Unicellular, colonial or multicellular (e.g. Giant kelp
– 65m in length), often flagellated predecessors of
higher plants
THE DIFFERENT KINGDOMS
CONT…
PLANTAE
Multi-cellular
Cellulose cell walls
Mostly terrestrial
Chlorophyll – photosynthesis – autotrophic
Different specialized cells grouped together to form
different functions
• Reproduce sexually or asexually
•
•
•
•
•
THE DIFFERENT KINGDOMS CONT…
•
•
•
•
•
FUNGI
About 800 million years ago –Precambrian
Terrestrial but dependent on moisture
Heterotrophs + saprophytes
Enzymes digest the substrate – nutrients absorbed
into their bodies
Harmful/useful
THE DIFFERENT KINGDOMS CONT…
•
•
•
•
ANIMALIA
Multicellular
Heterotrophs
Specialized cells form tissues
Tissues form organs