Transcript Classification: Georgia Performance Standards:

Classification:
Georgia Performance Standards:
SB3. Students will derive the relationship between single-celled
and multi-celled organisms and the increasing complexity of
systems.
b. Compare how structures and function vary between the six
kingdoms (archaebacteria,eubacteria, protists, fungi, plants, and
animals).
c. Examine the evolutionary basis of modern classification systems.
d. Compare and contrast viruses with living organisms.
SB5. Students will evaluate the role of natural selection in the
development of the theory of evolution.
e. Recognize the role of evolution to biological resistance (pesticide
and antibiotic resistance).
Essential Questions:
1.How does the evidence of evolution contribute to
modern classification systems?
2.Why classify?
3. On what criteria do Taxonomists base their
classification of organisms?
4.Are viruses alive?
5. What is the role of evolution in antibiotic and
pesticide resistance?
Classification of Living Things
Why Classify?
• To study the diversity of life, biologists use a
classification system to name organisms and
group them in a logical manner.
• In taxonomy, scientists classify organisms and
assign each organism a universally accepted
name.
Why do scientists classify?
• Biologists classify living organisms to
answer questions such as:
- How many known species are there?
- What are the defining characteristics of each
species?
- What are the relationships between these
species?
Aristotle
• Aristotle
– Greek philosopher
and teacher more
than 2000 years
ago
– The first person to
group or classify
organisms
(300 B.C.)
Aristotle
PLANTS:
Based on
size of stem
ANIMALS:
Based on
where they lived
Limitations of Early Classification
1. Not all organisms fit into
Aristotle’s
2 groups (plants or animals)
Ex:
Bacteria
Fungi
Images from: http://www.leighday.co.uk/upload/public/docImages/6/Listeria%20bacteria.jpg
http://danny.oz.au/travel/iceland/p/3571-fungi.jpg
Limitations of Early Classification
2. Common names can be misleading
Ex:
A jelly fish isn’t a fish,
but a seahorse is!
Sea cucumber
sounds like a plant
but… it’s an animal!
Image from: http://www.alaska.net/~scubaguy/images/seacucumber.jpg
Limitations of Early
Classification
3. Common names vary from
place to place
Ex: puma,
catamount,
mountain lion,
cougar
are all names
for same animal
Image from: http://www4.d25.k12.id.us/ihil/images/Cougar.jpg
Limitations of Early
Classification
4. Same organisms
have different
names in different
countries.
Chipmunk
Streifenhornchen (German)
Tamia (Italian)
Ardilla listada (Spanish)
Image from: http://www.entm.purdue.edu/wildlife/chipmunk_pictures.htm
Limitations of Early
Classification
• Early Solution:
–Description of
Organism
Using Latin
RED OAK
Names
Quercus foliis obtuse-sinuatis setaceo-mucronatis
“oak with leaves with deep blunt lobes bearing hairlike bristles”
Limitations of Early Classification
• Problem with Latin Name
descriptions?
- Names too long and difficult to
remember
- Names don’t illustrate evolutionary
relationships
Carolus Linneaus
Devised a new
classification
system based on
morphology
(Organism’s form
and structure)
(1707-1778)
“Father” of taxonomy and binomial nomenclature
Carolus Linnaeus
• Linnaeus’s Classification System
– Organisms grouped in a hierarchy of
seven different levels
– Each organism has a two part scientific
name
• Binomial Nomenclature
Early Efforts at Naming Organisms
• The first attempts at standard scientific names
often described the physical characteristics of a
species in great detail.
• Results in long names
• Difficult to standardize the names of organisms
• Different scientists described different
characteristics.
Binomial Nomenclature
• Carolus Linnaeus developed a two-word
naming system called binomial
nomenclature.
• In binomial nomenclature, each species
is assigned a two-part scientific name.
– First word is the genus
– Second word is the species
Binomial Nomenclature
• Binomial Nomenclature: Two name
naming system
– Italicized or Underlined
• 1st Name = Genus
– Capitalized
• 2nd Name = Species Identifier
– Lower case
Binomial Nomenclature
Vampire bat
Desmodus
rotundus
Image from: http://212.84.179.117/i/Vampire%20Bat.jpg
Eastern chipmunk
Tamias striatus
Image from: http://www.entm.purdue.edu/wildlife/chipmunk_pictures.htm
Binomial Nomenclature
Humans
Homo sapiens
Homo sapiens
Image from: http://www.earlylearning.ubc.ca/images/photo_baby.jpg
Linnaeus's System of Classification
• A group or level of
organization is called
a taxonomic category,
or taxon
• King Phillip Came Over
From Genoa Spain
• The are 7 taxonomic
categories. (from
smallest to largest)
• species
• genus
• family
• order
• class
• Phylum
• kingdom.
The 7 taxonomic categories
• Species - a group of organisms that breed with one
another and produce fertile offspring.
• Genus - a group of closely related species.
• Family - genera that share many characteristics.
• Order - is a broad taxonomic category composed of
similar families.
• Class - is composed of similar orders.
• Phylum- several different classes that share important
characteristics.
• Kingdom - largest taxonomic group, consisting of closely
related phyla
Kingdom
Phylum
Class
Order
Family
Genus
Species
Kids
Prefer
Cheese
Over
Fried
Green
Spinach
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Felidae
Genus Panthera
Species leo
http://www.vetmed.wisc.edu/dms/fapm/personnel/tom_b/2004-lion.jpg
Classification Pop Quiz:
1. How are living things organized for study?
2. Describe the system for naming species that Linnaeus
developed.
3. What are the seven taxonomic categories of Linnaeus’s
classification system from largest to smallest?
4. Why do scientists avoid using common names when
discussing organisms?
5. Based on their names, you know that the baboons Papio
annubis and Papio cynocephalus do NOT belong to the same
a. Class
b. family
c. Genus
d. species
Modern Taxonomy
• Organizes
living things
in the
context of
evolution
Modern Evolutionary Classification
• Organisms are grouped into categories that
represent lines of evolutionary descent, not just
physical similarities
• This strategy of grouping organisms together
based on their evolutionary history is called
evolutionary classification.
 Modern classification systems are based upon
biochemical and genetic evidence that indicates
evolutionary relationships
Modern Taxonomy:
Evolutionary Relationships
• Determined through
the use of:
1.
2.
3.
4.
5.
Morphology
Fossil Record
Embryology
Chromosomes
Macromolecules
Evolutionary
relationships can be
illustrated on a
phylogenetic tree
1. FOSSIL RECORD
We can trace some
changes over time
through the fossil
record.
Evolutionary
PHYLOGENY
history =
2. MORPHOLOGY
Shape and Function
Image from:
http://www.angelfire.com/ab7/evolution12/evolutionclues.html
Morphology
• Homologous Characteristics:
– Same embryological origin (may have
similar structure and function)
– Example: Bat Wing and Human Arm
Homologous characteristics suggest a
recent common ancestor
Morphology
Bat wing
and human arm
develop from
same embryonic
structures
HOMOLOGOUS
STRUCTURES
Morphology
• Analogous Characteristics:
– May have similar structure and function, but
different embryological origin
– Example: Bird Wing and Butterfly Wing
Analogous characteristics evolved
separately.
Organisms not necessarily closely related.
ANALOGOUS
STRUCTURES
Bird wing and
butterfly wing
have evolved with
similar function
BUT
different structure
inside.
http://uk.dk.com/static/cs/uk/11/clipart/bird/image_bird003.html
Insects and birds
NOT closely related!
http://www.naturenorth.com/butterfly/images/05a%20tiger%20wing.jpg
I don’t get it!
 Analogous characters  the same function
but different underlying construction.
 Homologous characters  different functions, but
show an anatomical similarity inherited from a
common ancestor. **Important for cladograms!**
3. Embryology
Animals whose embryos develop
in a similar pattern may be related
Image from: http://calspace.ucsd.edu/virtualmuseum/litu/03_3.shtml
Even differences show relatedness
amnion /am·ni·on/ (am´ne-on) bag of waters; the extraembryonic membrane of birds,
reptiles, and mammals, which lines the chorion and contains the fetus and the
amniotic fluid
http://www.southtexascollege.edu/nilsson/4_gb_lecturenotes_f/4_gb_24_cla_ani_ve_spr2003.html
4. Chromosomes
Similar karyotypes suggest closer relationships.
Human: http://www.nationmaster.com/wikimir/images/upload.wikimedia.org/wikipedia/en/thumb/1/18/300px-Human_karyogram.png
Chimpanzee: Middle School Life Science , published by Kendall/Hunt.
Human- 46 chromosomes
Chimpanzee- 48 chromosomes
Even differences show relatedness
Chimpanzees have 2 smaller chromosome pairs we don’t have
Humans have 1 larger chromosome pair (#2) they don’t have.
Human: http://www.nationmaster.com/wikimir/images/upload.wikimedia.org/wikipedia/en/thumb/1/18/300px-Human_karyogram.png
Chimpanzee: Middle School Life Science , published by Kendall/Hunt.
5. Macromolecules
• Comparison of macromolecules
such as Proteins and DNA
• Organisms with similar
sequences are (thought to be)
more closely related.
Macromolecules
Modern Evolutionary Classification
• Molecular Clocks
– Comparisons of DNA can • Comparison reveal how
dissimilar the genes
also be used to mark the
are.
passage of evolutionary
time.
– A model known as a
molecular clock uses
DNA comparisons to
estimate the length of
time that two species
have been evolving
independently.
• Degree of dissimilarity
is an indication of how
long ago the two
species shared a
common ancestor.
Phylogenetic Classification
• Phylogeny: the evolutionary history of a
species.
• Phylogenetic classification is a classification
system that shows the evolutionary history of a
species.
• Cladistics: It is assumed that a group of
organisms diverged and evolved from a common
ancestral group.
• Derived traits: Characteristics of the original
group that are retained.
Classification Using Cladograms
• Cladistic analysis identifies and considers only
the characteristics that arise as lineages evolve
over time.
– Characteristics that appear in recent parts of a
lineage but not in its older members are called
derived characters.
– Derived characters can be used to construct a
cladogram, a diagram that shows the evolutionary
relationships among a group of organisms.
Traditional Classification Versus Cladogram
Section 18-2
Appendages
Crab
Conical Shells
Barnacle
Limpet
Crustaceans
Crab
Gastropod
Barnacle
Limpet
Molted
exoskeleton
Segmentation
Tiny free-swimming larva
TRADITIONAL
CLASSIFICATION
Go to
Section:
CLADOGRAM
Cladistics
• Shows evolutionary relationships based on
“shared derived characteristics”
• Cladistic relationships illustrated through the
use of a Cladogram
Phylogeny:
Evolutionary History
• Cladogram: a branching diagram using
cladistics.
•
Image taken from:http://evolution.berkeley.edu/evolibrary/article//evo_03
Cladogram
 The greater the
number of derived
characters shared
by groups, the
more recently the
groups share a
common ancestor.
Checkpoint Questions:
1. How is information about evolutionary relationships
useful in classification?
2. How are genes used to help scientists classify
organisms?
3. What is the principle behind cladistic analysis?
4. Describe the relationship between evolutionary time and
the similarity of genes in two species.
5. How have new discoveries in molecular biology affected
the way in which we classify organisms compared with
the system used by Linnaeus?
Constructing a Chart
Modern Taxonomy
• Modern taxonomy involves the use of Linnaeus’s
naming/classification system, but with additional
kingdoms.
Domains
• Domains are taxonomic groups that are
even bigger than kingdoms. Each of the
six kingdoms belongs to a single domain.
• Three Domains:
– 1. Archaea
– 2. Bacteria
– 3. Eukarya
Do
Kids
Prefer
Cheese
Over
Fried
Green
Spinach?
The Three-Domain System
• The domain is the most inclusive taxonomic
category; larger than a kingdom
• The three domains are:
– Bacteria : kingdom Eubacteria
– Archaea,: kingdom Archaebacteria;
– Eukarya :Kingdom protists, fungi, plants, and
animals.
Domain Archaea
 Archaea are thought to be more ancient than
bacteria and yet more closely related to our
eukaryote ancestors.
 Cell walls without
peptidoglycan
 They are called extremophiles because
they can live in extreme environments.
Kingdom Archaebacteria
• Some archaebacteria are
heterotrophs, but some are
autotrophs.
• Most archaebacteria are unable to
move, but a few can move.
• Archaebacteria are the old known life
forms.
• Why are archaebacteria not classified
with “modern bacteria”?
– Archaebacteria and eubacteria
are chemically different!
Kingdom Archaebacteria
• Cool archaebacteria info:
• Three divisions of archaebacteria:
Methanogens: methane producing organisms
Thermophiles: These can live in extremely hot, acidic
environments like sulfur springs.
Halophiles: Can only live in bodies of concentrated salt water,
like the Dead Sea.
Domain Bacteria
 Eubacteria are
prokaryotes whose
cell walls contain
peptidoglycan.
 “True bacteria”
Kingdom Eubacteria
• Unlike archaebacteria, eubacteria require
oxygen.
• Some bacteria contain cilia or flagella
which allows them to move.
• Traditional prokaryotic bacteria
Kingdom Eubacteria
• Unicellular.
• Some are autotrophic, some are
heterotrophic.
• Found in soil, water, human body, etc.
• Esterichia coli (E. coli) is found in large
numbers in human intestines, where it
produces vitamin K.
Bacteria and Viruses
Mutations
 Bacteria reproduce quickly and their
population grows rapidly.
 Mutations lead to new forms of genes,
new gene combinations, new
characteristics, and genetic diversity.
 Rapid mutations cause bacteria to become
resistant to many antibiotics and
pesticides.
Domain Eukarya
 All eukaryotes are classified in Domain
Eukarya.
 Domain Eukarya contains Kingdom
Protista, Kingdom Fungi, Kingdom Plantae,
and Kingdom Animalia.
Organizing Life’s Diversity
Kingdom Protista
Protists are eukaryotic organisms that can
be unicellular, colonial, or multicellular
.
 Protists are
classified into three
different groups—
plantlike, animallike, and
funguslike.
Kingdom Protista
• “Junk Drawer Kingdom” or “Odds and Ends
Kingdom” Most Diverse Kingdom
• Some protists are autotrophic, some protists are
heterotrophic.
– Animal-like protists, plant-like protists
• Most protists are able to move, but some
cannot
Kingdom Protista
Organizing Life’s Diversity
Kingdom Fungi
A fungus is a unicellular or multicellular
eukaryote that absorbs nutrients from
organic materials in its environment.
Kingdom Fungi
• Fungal cell walls contain chitin.
– (cell walls of plants contain
cellulose).
• Usually, the only fungi that we see are
reproductive structures like Molds and
mushrooms.
• The study of fungi is known as
mycology.
• Fungi are more closely related to
animals than to plants!
Organizing Life’s Diversity
Kingdom Plantae
 Members of Kingdom Plantae form the
base of all terrestrial habitats.
 All plants are
multicellular and
have cell walls
composed of
cellulose.
 Most plants are
autotrophs, but some
are heterotrophic.
Kingdom Plantae
• Plants are eukaryotic,
multicellular organisms.
• They are autotrophs- they
make their food through
photosynthesis.
• Plants can be found on land
and in shallow water (where
there is light)
Kingdom Plantae
• Plant cells have cell walls
– Made up of cellulose, to provide them with a
rigid structure
• Some plants reproduce through both
asexual and sexual reproduction.
Kingdom Animalia
• This kingdom contains many
complex, multicellular
organisms.
• All animals are
heterotrophic.
• All animals are able to
move, even if it is only
during some stages of the
life cycle.
Kingdom animalia
• All animals are eukaryotic
organisms, but animal cells do
not have a cell wall.
• Most animals reproduce
through sexual reproduction,
but some are able to reproduce
asexually (or both!).
• The most simple organism
in the kingdom animalia
is a sponge.
Chapter
17
Organizing Life’s Diversity
17.3 Domains and Kingdoms
Kingdom Animalia
 All animals are heterotrophic, multicellular
eukaryotes.
 Animal organs often are
organized into complex
organ systems.
 They live in the water,
on land, and in the air.
Key Characteristics of Kingdoms and Domains
Classification of Living Things
DOMAIN
Bacteria
Archaea
KINGDOM
Eubacteria
Archaebacteria
CELL TYPE
Prokaryote
Prokaryote
CELL
Cell walls with
STRUCTURES peptidoglycan
NUMBER OF
CELLS
MODE OF
NUTRITION
Cell walls
without
peptidoglycan
Unicellular
Unicellular
Autotroph or
heterotroph
Autotroph or
heterotroph
Streptococcus, Methanogens,
Escherichia
halophiles
EXAMPLES
coli
Go to
Section:
Eukarya
Protista
Fungi
Plantae
Animalia
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Cell walls of
cellulose;
chloroplasts
No cell walls
or
chloroplasts
Most
unicellular;
some
colonial;
some
multicellular
Most
multicellular
; some
unicellular
Multicellular
Multicellular
Autotroph
Heterotroph
Autotroph or
heterotroph
Heterotroph
Amoeba,
Paramecium,
slime molds,
giant kelp
Mushrooms
, yeasts
Mosses,
ferns,
flowering
plants
Sponges,
worms,
insects,
fishes,
mammals
Section 18-3
Living
Things
are characterized by
Eukaryotic
cells
and differing
Important
characteristics
which place them in
Cell wall
structures
such as
Domain
Eukarya
Prokaryotic cells
which is subdivided into
which place them in
Domain
Bacteria
Domain
Archaea
which coincides with
which coincides with
Kingdom
Eubacteria
Kingdom
Archaebacteria
Go to
Section:
Kingdom
Plantae
Kingdom
Fungi
Kingdom
Protista
Kingdom
Animalia
The Six Kingdoms
• Kingdom Archaebacteria: Bacteria that live
in extreme environments void of oxygen. Cell
membrane lipids, RNA, and cell wall
structures are different than other bacteria.
• Kingdom Eubacteria: all other bacteria.
Strong cell walls and less complicated
genetic makeup. Live in many habitats
•
• Kingdom Protista: Eukaryote that lacks
complex organ systems and lives in moist
environments. Can be unicellular or
multicellular
The Six Kingdoms Continued
• Kingdom Fungi: Heterotrophs that do not move
from place to place. Uni or multicellular eukaryotes
that absorb nutrients from organic material.
• Kingdom Plantae: Multicellular photosynthetic
eukaryotes. Can not move from place to place.
Cells organized into tissues, tissues organized into
organs.
• Kingdom Animalia: Animals: multicellular
heterotrophs. Able to move from place to place. No
cell walls. Cells form tissues that form organs that
form organ systems.
Dichotomous Keys
• A tool used to identify organisms is a dichotomous key.
• A dichotomous key is a series of paired statements that
describe physical characteristics of different organisms.
• In this activity, you will use a dichotomous key to identify tree
leaves.
Checkpoint Questions:
1.
What are the six kingdoms of life as they are now
identified?
2.
What are the three domains of life?
3. Why was the kingdom Monera divided into two separate
kingdoms?
4. Why might kingdom Protista be thought of as the “odds
and ends” kingdom?
5. Which kingdoms include only prokaryotes? Which
kingdoms include only heterotrophs?