Classification
Grouping according to characteristics

Coevolution


Evolutionary change,
in which one species
act as a selective
force on a second
species, inducing
adaptations that in turn
act as selective force
on the first species.
Example:
1. Acacia ants and
acacia trees
2. Humming birds
and plants with
flowers with long
tubes
Praying mantis &
Orchid
Change Through Time
The History of Life
The Theory of Evolution
Primate Evolution
Organizing Life’s Diversity
Unit Overview – pages 366-367
Chapter 17
Organizing Life’s Diversity
17.1: Classification
17.2: The Six Kingdoms
Classification

How does grouping help us?

Easier to ID or locate “stuff”

Ex. Telephone number


Book in library
ID things by shared traits
Ch 17 Classification
What You’ll Learn

You will identify and

Evaluate the history,
compare various
purpose, and methods
methods of
of taxonomy.
classification.

Section Objectives:

You will distinguish
among six kingdoms of
organisms.
Explain the meaning of
a scientific name.

Describe the
organization of taxa in
a biological
classification system.
How Classification Began
• Taxonomy (tak SAH
nuh mee) is the branch
of biology that groups
and names organisms
based on studies of
Click image to view movie.
their different
characteristics.
• Biologists who study taxonomy are called
taxonomists.
Section 17.1 Summary – pages 443-449
Aristotle (384-322 B.C.)
- Early classification systems
Plants
by Size & structure
green & didn’t move



Herbs-soft stems
Shrubs-many trunks
Trees-1 trunk
Animals
 Habitat & physical
differences



Land
Air-birds, bats, & flying
insects
Water
While Aristotle’s classification system was used for
hundreds of years, some new discoveries that did not
fit into the groups required a new system.
Also, scientist wanted the same criteria used for all
organisms.
Binomial Nomenclature


Carolus von Linnaeus
Changes from Aristotle’s
system





Plants & animals further divided
into groups
System based on specific traits
Names described their traits
Grouped similar organisms into
species- having physical and structural
similarities
As a result, the groupings revealed the
relationships of the organisms
Carolus von
Linnaeus
(1707-1778)
Swedish scientist who
laid foundation for
modern taxonomy
Modern classification systems
Carolus Linnaeus


Two-word naming system

Genus

Noun, Capitalized,
Underlined or

Italicized

Species (specific epithet)

Descriptive, Lower
Case,
Underlined or
Italicized

The scientific name,
referred to as the species
name, is a combination of
the genus name and
specific epithet.
Scientific names should be
italicized in print and
underlined when
handwritten.
The first letter of the genus
name is uppercase, but the
first letter of the specific
epithet is lowercase.
Why use Scientific name?
Homo sapiens

No mistake about organism b/c it
only has one name


Cougar, puma, panther, mtn lion
A comman name may be misleading
(sea horse is a fish)

Scientific names seldom change

All are written in same language
(Latin) (dead-doesn’t change)
Taxonomy: A framework


Taxonomists group similar

Taxonomists try to
organisms, both living and
identify the evolutionary
extinct.
relationships as a basis for
Classification provides a
classification
framework in which to

study the relationships
among living and extinct
species
easier to understand
biological diversity.

can be a useful tool in
agriculture, forestry, and
medicine
Dichotomous Keys Identify
Organisms



Dichotomous keys vs.
evolutionary classification
Dichotomous keys contain pairs of
contrasting descriptions.
After each description, the key
directs the user to another pair of
descriptions or identifies the
organism.
Dichotomous key- identify organisms
Taxonomy: A useful tool

A key is made up of sets of numbered
statements. Each set deals with a single
characteristic of an organism, such as leaf
shape or arrangement.
Dichotomous Keys Identify
Organisms

Example:
1. a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
2. a) Are margins of the leaf jagged?
Go to 4
b) Are margins of the leaf smooth?
Go to 5
Classification can change with
expanding knowledge about new and
well known organisms

Spanish moss

Pineapple
Checking your understanding




What traits were used by Aristotle to
divide plants into groups?
How did Linnaeus change the
classification system?
Name 7 classification groups in order.
Why would Aristotle have problems
classifying an organism that moved, but
was green with chloroplast?
How scientist classify today

Classification based on



how organisms are related
Evolutionary relationshipsAncestors
Body chemistry
Taxonomy and the economy

It often happens that the discovery of new sources of lumber,
medicines, and energy results from the work of taxonomists.

The characteristics of a familiar species are frequently similar
to those found in a new, related species.

For example, if a taxonomist knows that a certain species of
pine tree contains chemicals that make good disinfectants,
it’s possible that another pine species could also contain
these useful substances
How Living Things Are Classifiedmaking them easier to find and discuss



A group of organisms is called a taxon (plural,
taxa).
Organisms are ranked in taxa that range from
having very broad characteristics to very
specific ones.
The broader a taxon, the more general its
characteristics, and the more species it
contains.
Taxonomic rankings
• Compare the appearance of a lynx, Lynx
rufus, a bobcat, Lynx canadensis, and a
mountain lion, Panthera concolor.
Lynx
Bobcat
Mountain
lion
Section 17.1 Summary – pages 443-449
Domain
Eukarya
Kingdom
Animalia
Chordata
Phylum
Class
Mammalia
Carnivora
Order
Family
Genus
Felidae
Lynx
Species Lynx
canadensis
rufus Lynx
Bobcat Lynx
Section 17.1 Summary – pages 443-449
Question 1
How did Aristotle group organisms
such as birds, bats, and insects?
A. by their common genus
B. by their analogous structures
C. by their common species
D. by their homologous structures
The answer is B. The organisms were grouped
together because of their wings, which, in this
case, are analogous structures.
Question 2
Which taxon contains the fewest species?
A.
B.
C.
D.
genus
family
order
phylum
The answer is A, genus.
Question 3
For which of the following species names
does the specific epithet mean “handy?”
A. Homo sapiens
B. Homo erectus
C. Australopithecus anamensis
D. Homo habilis
The answer is D.
Question 4
What is the difference between
“classification” and “taxonomy?”
Answer
Classification is the grouping of objects or
information based on similarities. Taxonomy
is the branch of biology that classifies and
names organisms based on their different
characteristics.
Section 1 Check
Question 5
What are the two parts that make
up binomial nomenclature?
Answer
Binomial nomenclature comprises a genus
name followed by a specific epithet.
17.2 The 6 Kingdoms



Describe how evolutionary relationships are
determined.
Explain how cladistics reveals phylogenetic
relationships.
Compare the six kingdoms of organisms.
Used like
address
•Planet
Hierarchical Classification
•Continent
 Taxonomic categories
•Country
 Kingdom
King
•State
 Phylum
Philip
•County
 Class
Came
•City
 Order
Over
•Street



Family
Genus
Species
For
Green
Soup
Allows for
specific
identification




Evidence of
Modern
classification
systems
Same ancestors
Similar body
structure
Body chemistry

Genetics may
indicate
relationships
between
organisms
with similar
DNA codes.
Cladistics

Cladistic based on phylogeny (evolutionary history)

Taxonomist assumes that as groups of organisms diverge and evolve
from a common ancestral group, they retain some unique inherited traits.

A difference between cladograms and pedigrees is that, pedigrees show
the direct ancestry of an organism from two parents, cladograms show a
probable evolution of a group of organisms from ancestral groups
Taxonomic Diagrams
Mammals
Turtles
Lizards and
Snakes
Crocodiles
Birds
Mammals
Turtles
Lizards and
Snakes
Cladogram
Phylogenetic Tree- depict
the evolutionary
relationships of a group of
organisms.
Crocodiles
Birds
•similar to phylogenic tree
•demonstrates where they evolved
from common ancestors
•uses more reliable information like
genetic and biochemical analysis to
determine the relationships
How are evolutionary relationships
determined?
Evolutionary relationships are
based on similarities in

Structure

breeding behavior

geographical distribution

Chromosomes

biochemistry.
Structural
similarities


Structural similarities
among species
reveal relationships.
The presence of many
shared physical
structures implies that
species are closely
related and may have
evolved from a
common ancestor.


classify dandelions and
sunflowers in the same
family, Asteraceae,
because they have
similar flower and fruit
structures
infer their evolutionary
history.
Breeding behavior


breeding behavior provides important clues to
relationships among species
For example, two species of frogs, Hyla
versicolor and Hyla chrysoscelis, live in
the same area and look similar. During the
breeding season, however, there is an obvious
difference in their mating behavior. Scientists
concluded that the frogs were two separate
species
Geographical
distribution
•
These finches probably
spread into different
niches on the volcanic
islands and evolved
over time into many
distinct species.

The fact that they
share a common
ancestry is supported
by their geographical
distribution in addition
to their genetic
similarities.
Chromosome
comparisons

Both the number and structure
of chromosomes, as seen
during mitosis and meiosis,
provide evidence about
relationships among species.

For example, cauliflower,
cabbage, kale, and broccoli look
different but have
chromosomes that are almost
identical in structure.
Therefore, biologists
propose that these
plants are related.
Biochemistry


Powerful evidence about relationships among
species comes from biochemical analyses of
organisms Closely related species have
similar DNA sequences and, therefore,
similar proteins.
In general, the more inherited nucleotide
sequences that two species share, the more
closely related they are.
Phylogenetic Classification: Models

The evolutionary history of a species is called its
phylogeny

A classification system that shows the evolutionary
history of species is a phylogenetic classification
and reveals the evolutionary relationships of
species
Fan Model of
6 Kingdoms

a fanlike model may
communicate the time
organisms became extinct or
the relative number of species
in a group.

A fanlike diagram incorporates
fossil information and the
knowledge gained from
anatomical, embryological,
genetic, and cladistic studies.
Archaebacteria
Eubacteria
Protists
Fungi
Plants
animals.
THE SIX KINGDOMS OF ORGANISMS
ARE
ARCHAEBACTERIA
EUBACTERIA
PROTISTS
FUNGI
PLANTS
ANIMALS.
In general, differences in cellular structures and methods
of obtaining energy are the two main characteristics that
distinguish among the members of the six kingdoms.
Kingdoms? (video)

Monerans- 1 cell w/o nucleus






Eubacteria
Archaebacteria- in extreme conditions
Protist- 1 cell w nucleus (may have
characteristics of plants & animals
Fungi-have cell walls but absorb food (no
chlorophyll)-mushrooms, yeast,
Plant-many cells, w chlorophyll, make
food- don’t move
Animal- many cells, can’t make food,
move
There is disagreement between
scientist over 5 or 6 kingdoms
Prokaryotes

The prokaryotes,
organisms with cells that
lack distinct nuclei
bounded by a membrane,
are microscopic and
unicellular. Some are
heterotrophs and some
are autotrophs.

some prokaryotic
autotrophs are
chemosynthetic,
whereas others are
photosynthetic.
Monerans- 1 cell w/o nucleus


Eubacteria
true bacteria,
characterized by
their rigid cell
walls

Archaebacteria- in
extreme
conditions
There are two kingdoms of
prokaryotic organisms
Eubacteria

have very strong cell walls and a less
complex genetic makeup than found
in archaebacteria or eukaryotes
Archaebacteria

most live in extreme env. such as
swamps, deep-ocean hydrothermal
vents, & seawater evaporating
ponds

Most of these environments are
oxygen-free

live in most habitats

Although some eubacteria cause
diseases, such as strep throat &
pneumonia, most bacteria are
harmless and many are actually
helpful.
Protist- a eukaryote -lacks complex organ
systems and lives in moist env.






Uni or multicell
& properties of
plants (autotrophs)
animals
(heterotroph)
funguslike
heterotrophs
(produce
reproductive
structures like
those of fungi.)
Fungi






Do not move
Uni/multicell
cell walls but
absorb
nutrients
from organic
materials
(no
chlorophyll)
mushrooms,
yeast
There are more
than 50,000
known species
of fungi.
Plant- make fooddon’t move




All are multicellular
Photosynthetic (autotroph)
(chlorophyll/chloroplast)
Cell walls of cellulose
eukaryotes.
Plants:
Multicellular
oxygen producers



The oldest plant fossils
are more than 400 million
years old.
some scientists propose
that plants existed on
Earth’s landmasses much
earlier than these fossils
indicate.
There are more than
250,000 known species of
plants





Types
flowering plants
Mosses
Ferns
evergreens.
Animal- multicells, heterotrophs,
(can’t make food), move


No cell walls
Animals first appeared
in the fossil record
about 600 million
years ago
Question 1
Which of the following is NOT a way to
determine evolutionary relationships?
A. chromosome comparisons
B. biochemistry
C. specific epithets
D. geographical distribution
The answer is C.
Question 2
How does a cladogram differ from a pedigree?
Answer
Pedigrees show the direct ancestry of an
organism from two parents. Cladograms show
a probable evolution from an ancestral group.
Question 3
Allosaurus
Velociraptor
Robin
Archaeopteryx
Sinornis
Theropods
Feathers with Flight feathers;
3-toed
foot;
Down
Light bones
arms as long
shaft, veins,
wishbone feathers
as legs
and barbs
Using the cladogram, which of the following
traits would be a primitive trait?
Question 3
Allosaurus
Velociraptor
Robin
Archaeopteryx
Sinornis
Theropods
Feathers with Flight feathers;
3-toed
foot;
Down
Light bones
arms as long
shaft, veins,
wishbone feathers
as legs
and barbs
A. down feathers
C. light bones
B. arms as long as legs
D. flight feathers
Allosaurus
Velociraptor
Robin
Archaeopteryx
Sinornis
Theropods
Feathers with Flight feathers;
3-toed
foot;
Down
Light bones
arms as long
shaft, veins,
wishbone feathers
as legs
and barbs
The answer is C. Primitive traits are traits
that evolved very early.
Question 4
Why do taxonomists use Latin
names for classification?
Answer
Latin is no longer used in conversation
and, therefore, does not change.
Question 5
What is the relationship between
cladistics and taxonomy?
Answer
Cladistics is one kind of taxonomy
that is based on phylogeny.
Classification
• Although Aristotle developed the first
classification system, Linnaeus laid the
foundation for modern classification
systems by using structural similarities to
organize species and by developing a
binomial naming system for species.
• Scientists use a two-word system called
binomial nomenclature to give species
scientific names.
Classification
• Classification provides an orderly framework
in which to study the relationships among
living and extinct species.
• Organisms are classified in a hierarchy of
taxa: domain, kingdom, phylum or division,
class, order, family, genus, and species.
The Six Kingdoms
• Biologists use similarities in body structures,
breeding behavior, geographic distribution,
chromosomes, and biochemistry to determine
evolutionary relationships.
• Modern classification systems are based
on phylogeny—the evolutionary history
of a species.
The Six Kingdoms
• Kingdoms Archaebacteria and Eubacteria contain
only unicellular prokaryotes.
• Kingdom Protista contains eukaryotes that
lack complex organ systems.
• Kingdom Fungi includes heterotrophic
eukaryotes that absorb their nutrients.
The Six Kingdoms
• Kingdom Plantae includes multicellular
eukaryotes that are photosynthetic.
• Kingdom Animalia includes multicellular,
eukaryotic heterotrophs with cells that
lack cell walls.
Domain
Eukarya
Kingdom
Animalia
Chordata
Phylum
Class
Mammalia
Carnivora
Order
Family
Genus
Felidae
Lynx
Species Lynx
canadensis
rufus Lynx
Bobcat Lynx
Question 1
Both organisms are members of the same
kingdom, phylum, class, order, family, and
genus but belong to different species.
Question 2
Which taxon contains the others?
A. order
B. class
C. genus
D. family
The answer is B.
Question 3
Which of the following pairs of terms
is NOT related?
A. specific epithet – genus
B. binomial nomenclature – Linnaeus
C. biology – taxonomy
D. Aristotle – evolutionary relationships
The answer is D.
Domain
Eukarya
Kingdom
Animalia
Chordata
Phylum
Class
Mammalia
Carnivora
Order
Family
Genus
Felidae
Lynx
Species Lynx
canadensis
rufus Lynx
Bobcat Lynx
Question 4
Domain
Eukarya
Kingdom
Animalia
Chordata
Phylum
Class
Mammalia
Carnivora
Order
Family
Genus
Felidae
Lynx
Species Lynx
canadensis
rufus Lynx
Bobcat Lynx
Bobcats
are more
closely
associated
with
lynxes as
cats than
as
mammals.
Question 5
What two main characteristics distinguish
the members of the six kingdoms?
Answer
The two characteristics are differences
in cellular structures and methods of
obtaining energy.
Question 6
Which of the following is NOT true of both
the animal and plant kingdoms?
A.
B.
C.
D.
both contain organisms made up of cells
tissues are organized into organs
cells are organized into tissues
cells contain cell walls
The answer is D.
Question 7
Which of the following describes a fungus?
A. autotrophic prokaryote
B. unicellular or multicellular heterotroph
C. unicellular autotroph
D. heterotrophic prokaryote
The answer is B, unicellular
or multicellular heterotroph.
Question 8
What is a dichotomous key?
Answer
A dichotomous key is a set of paired statements
that can be used to identify organisms.
Question 9
How has DNA-DNA hybridization shown
that flamingoes are more closely related to
storks than they are to geese?
When DNA from storks and flamingoes was
allowed to bond, DNA base pairs matched and the
strands bonded more strongly than when DNA
from flamingoes and geese was allowed to bond.
Stork
Flamingo
Question 10
Why do some scientists believe that plants
existed on Earth’s landmasses much earlier
than fossils indicate?
Answer
Plants do not fossilize as often as organisms
that contain hard structures, like bones, which
more readily fossilize than soft tissues.