Unit 1 Lesson 2
Classifying Organisms
• What methods are used to classify
living things into groups?
• Why does every species have a
scientific name?
Classify
to arrange things into groups
Classification:
the process of
grouping things
based on their
similarities
Taxonomy
(from Gk. taxis –
arrangement, order)
the science of classifying organisms
into groups
Two types of objects
Inanimate:
“not living”
Animate:
“possessing life”
Classifying Living Things
• There have been many different ideas
about how to organize, or classify,
living things.
• Aristole classified organisms into two
main groups: plants & animals
• Carolus Linnaeus classified organisms
into two main groups, called
kingdoms, based on similar structures.
What evidence is used
to classify living things
into groups?
· Cell type, complex or simple
· Their ability to make food
· The number of cells in their body
Classifying Living Things
• The current classification method for
organisms is called systematics.
• Systematics uses all known evidence
to classify organisms, including cell
type, how food and energy are
obtained, structure and function of
features, common ancestry, and
molecular analysis.
The Classification Hierarchy
First recorded
classification of
organisms was
attempted by Aristotle
the Greek scientist and
philosopher.
Aristotle’s Classification System
Plants
HERBS - if they lacked woody parts
SHRUBS - if they had several short
woody stems
TREES - one large woody stem .
Aristotle’s Classification System
Animals
FISH – swim
BIRDS - fly
LAND ANIMALS - walk
artificial classification system
based on appearance
(physical characteristics)
Aristotle's system was used for
approximately 2,000 years.
(used into the 1600’s)
Carolus Linnaeus
In the 1700's Carolus
Linnaeus, a Swedishnaturalist, discovered
problems in the
systematic arrangement
for botany and began to
sketch his own
classification method.
Carolus Linnaeus set forth a new
classification system in his works
(books he wrote).
• Species Plantarum
• Systema Naturae
Species Plantarum
• published 1753
• forms the basis
for plant
classification
Systema Naturae
• published 1753
• forms the basis
for plant
classification
Carolus Linnaeus
Linnaeus is known
as the father of
modern biological
classification or the
father of
taxonomy.
Carolus Linnaeus
Linnaeus also established the modern scientific
method of naming plants and animals.
His system is also an artificial classification
system (based on physical characteristics).
It has more flexibility than the previous systems.
It is still used today.
Linnaeus's 7 Basic Levels of Classification
His system has 7 basic levels (largest --->smallest)
kingdom
phylum (division)
class
order
family
genus
species
Species are often divided into sub-species (or varieties – like
dogs). Subphyla & subclasses may also be used.
kingdom
Science Use a classification
category that ranks above
phylum and below domain
Common Use a territory ruled by
a king or a queen
The more
classification levels
that two organisms
share, the more
characteristics they
have in common.
As you move down
the levels there are
fewer kinds of
organisms in each
group.
Organisms are placed into domains and
kingdoms based on their cell type, their
ability to make food, and the number of cells
in their bodies.
Levels of Classification
Some
classification
systems have
an eighth level
– domain –
that is a level
higher than
kingdom.
Levels of Classification
Organisms are now classified into
one of three domains and then
into one of six kingdoms.
Unicellular prokaryotes
The "true bacteria". Examples: Enteric bacteria
like E. coli, Salmonella typhus, Legionella,
Heliobacter pylorii (cause of many ulcers),
Neisseria gonorrhea (cause of gonorrhea),
Nitrogen-fixing bacteria that are able to convert
nitrogen gas into ammonia. Clostridium
(tetanus, botulism).
also unicellular prokaryotes but they are
found in some of the most extreme
environments on Earth (such as hot
springs, very salty water, swamps, volcano
vents in the Pacific Ocean floor, and the
intestines of cows)
Protist
Fungi
Animal
Plant
The Six Kingdoms
Kingdom Archaebacteria
Kingdom Eubacteria
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Kingdom Archaebacteria
In 1983, scientists tool samples from a spot deep in the
Pacific Ocean where hot gases and molten rock boiled into
the ocean form the Earth’s interior. To their surprise they
discovered unicellular (one cell) organisms in the samples.
These organisms are today classified in the kingdom,
Archaebacteria.
Archaebacteria are found in
extreme environments such as
hot boiling water and thermal
vents under conditions with no
oxygen or highly acid
environments.
Kingdom Eubacteria
Like archaebacteria, eubacteria are complex and
single celled. Most bacteria are in the
EUBACTERIA kingdom. They are the kinds found
everywhere and are the ones people are most familiar
with. Eubacteria are classified in their own kingdom
because their chemical makeup is different.
Most eubacteria are helpful.
Some produce vitamins and
foods like yogurt. However,
some eubacteria, Streptococci,
can give you strep throat!
Kingdom Protista
Slime molds and algae
are protists.
Sometimes they are
called the odds and
ends kingdom because
its members are so
different from one
another. Protists
include all microscopic
organisms that are not
bacteria, not animals,
not plants and not
fungi.
Most protists are unicellular. You may
be wondering why those protists are
not classified in the Archaebacteria or
Eubacteria kingdoms.
It is because, unlike bacteria, protists
are complex cells.
Kingdom Fungi
Fungi are
organisms that
biologists once
confused with
plants, however,
unlike plants,
fungi cannot
make their own
food. Most obtain
their food from
parts of plants
that are decaying
in the soil.
Mushrooms, mold and
mildew are all
examples of organisms
in the kingdom fungi.
Most fungi are
multicellular and
consists of many
complex cells.
Kingdom Plantae
With over 250,000 species, the plant kingdom is the
second largest kingdom. Plant species range from the
tiny green mosses to giant trees.
Plants are autotrophs, organisms that
make their own food.
You are probably
quite familiar with
the members of
this kingdom as it
contains all the
plants that you
have come to know
- flowering plants,
mosses, and ferns.
Plants are all
multicellular and
consist of complex
cells.
Kingdom Animalia
All animals consist of many complex cells. They are also
heterotrophs.
Members of the animal kingdom are found in the most
diverse environments in the world
The animal kingdom is the largest
kingdom with over 1 million known
species.
What about Humans?
Man is not an
animal; he is
God’s highest
creation and
created in God’s
image.
Christian Classification System?
Why don’t Christians invent a
“Christian Classification System” that
would not be influenced by
evolutionary bias? Any new system
that uses physical characteristics as the
basis for classification would likely
group organisms quite similarly to the
current system.
Christian Classification System?
There is a Christian classification system
that has been proposed called
baraminology. The term baraminology
comes from the Hebrew words bara,
meaning “create,” and min, meaning
“kind.” Baraminology attempts to classify
organisms according to their biblical kind.
Christian Classification System?
Since one of the primary functions of a
classification system is to eliminate confusion
regarding organisms, having a separate system
that is similar but not really parallel would likely
add confusion rather than eliminate it. A more
reasonable solution is for Christians to accept
the Bible as the source of all truth and reject any
evolutionary bias found in the current system..