Order From Chaos

1
Order From Chaos
Section 18-1
Interest Grabber

• When you need a new pair of shoes, what do you
  do? You probably walk confidently into a shoe
  store, past the tens or hundreds of pairs of
  shoes you dont want and straight to the kind you
  do want. How do you find them? Shoes are
  organized in the store in categories. People
  organize objects by grouping similar objects
  together.

Go to Section
2
Section 18-1

• 1. Consider the task facing early biologists who
  attempted to organize living things. How might
  they have begun?
• 2. Suppose that you have been given a green
  plant, stringy brown seaweed, a rabbit, a
  mushroom, a worm, and a grasshopper. Youve been
  asked to organize these things into categories
  that make sense. How would you do it?
• 3. Decide on your categories and write each on a
  sheet of paper. Next to each category, write the
  defining characteristics of that category. Then,
  write in the organisms that fall into each
  category.

Go to Section
3
Section Outline
Section 18-1

• 181 Finding Order in Diversity
• A. Why Classify?
• B. Assigning Scientific Names
• 1. Early Efforts at Naming Organisms
• 2. Binomial Nomenclature
• C. Linnaeuss System of Classification

Go to Section
4
KEY CONCEPT Organisms can be classified based on
physical similarities.
5

• What is the purpose of classification?
• Taxonomy
• The study of classification and giving each
  organism a unique name.
• Why not use common names?
• Binomial Nomenclature
• The 2-part scientific name each species is given.
• Genus
• A group of closely related species.
• Taxon A group or level of organization

6
Classification

• grouping of objects based on similarities
  (clothes, dishes, etc.)
• Humans like to organize their world so early on
  we grouped or classified everything we saw.
• .

7
Systematics

• classification system that groups organisms
  according to evolutionary relationships
• Based on common descent (idea that any two
  organisms can trace back to a common ancestor)
• identifies species, determines their
  relationships to known organisms, and gives them
  names.

8
1. Organize huge amounts of information
1.5 million species named A MINIMUM of 10
million different kinds of organisms expected
9
2. Accurate identification of existing and new
species
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0538.jpg
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3. Consistent names for communication

• Cougar, mountain lion, snow cat, screaming cat,
  panther, puma
• 30 common names

11
Scientific names help scientists to communicate.

• Some species have very similar common names.
• Some species have many common names.

12
4. Demonstrates relationships between organisms
13
5. Make hypotheses about life
http//www.mc.maricopa.edu/dept/d10/asb/origins/ho
minid_journey/central.html
14

• SPECIES Group of similar organisms that can
  mate and produce offspring
• Number of species of living organisms in the
  world? Probably a minimum of 10 million different
  organisms.
• HOW can we group and name these organisms?
• Classify to organize things into GROUPS based
  upon
• HOW do grocery stores classify different things?
• HOW do department stores classify different
  things?

15

• Problem with common names
• 1) Names are not the same in all languages
• 2) Names in different countries mean different
  things - corn in England means callus
• NEED a system of classification that is
  understood by ALL scientists throughout the world
  Binomial Nomenclature (understood by everyone
  in the world)

16
History of ClassificationAristotle (Greek
philosopher 384-322 B.C.)

• developed the first accepted system of
  biological classification
• Grouped organisms by how they looked

http//westernparadigm.files.wordpress.com/2008/10
/aristotle.jpg
17
Aristotle

• PROBLEMS
• Birds, bats, and flying insects together even
  though little in common besides ability to fly.
• Very few groups - as more organisms discovered ,
  many did not fit easily into Aristotles groups.
• BUT Many centuries passed before Aristotles
  system was replaced.

18
Linnaeus developed the scientific naming system
still used today.

• Taxonomy is the science of naming and
  classifying organisms.

White oakQuercus alba
A taxon is a group of organisms in a
classification system.
19
History of ClassificationCarolus Linnaeus (Carl
von Linné) (Swedish Botanist 1707-1778)"Father
of Modern Classification"
1. Binomial Nomenclature Developed a naming
system for giving each group a unique two part
scientific name

• 2. Hierarchical Classification
• Organisms organized into groups of increasing
  inclusiveness by morphology

20

• Binomial nomenclature is a two-part scientific
  naming system.

• uses Latin words
• scientific names always written in italics
• two parts are the genus name and species
  descriptor

21
A genus includes one or more physically similar
species.

• Species in the same genus are thought to be
  closely related.
• Genus name is always capitalized.
• A species descriptor is the second part of a
  scientific name.
• always lowercase
• always follows genusname never written alone

Tyto alba
22
Binomial Nomenclature Linnaeus

• Bi (two) nomial (name)
• First part of name genus
• first letter ALWAYS capitalized
• Second part of name specific or species name
• first letter NEVER capitalized
• Both words UNDERLINED or in ITALICS
• LATIN based

23
Every species has a unique two part scientific
name.

• Panthera leo is the scientific name for an
  African lion
• Panthera (beasts) is the genus name
• leo (lion) is the specific
• name

24
Binomial Nomenclature - more

• Two different organisms cannot be given the same
  binomial name
• (may have same first name same genus or same
  second name if in different genera)
• Names usually have clues often
• Describes the appearance (Tyrannosaurus rex
  tyrant/lizard king)
• Describes the distribution (carolinensis from
  North/South Carolina)
• Describes the discoverer or famous scientist
  (darwinii)

25
Sugar Maple Acer saccharum
26
Brown Bear (Grizzly Bear) Ursus arctos
27
Great White Shark Carcharodon carcharias
28
Checkpoint

• What is systematics and why is it important?
• Who is Carl Linnaeus?
• Write the species name of humans according to
  Binomial nomenclature.
• What is a species?
• What is a genus?

ANY QUESTIONS?
29
Linnaean System is Hierarchal.

• Larger groups are more inclusive and smaller
  groups are more specific.
• For example, the phylum Chordata includes both
  lions and lionfish, but the genus Panthera
  includes only lions other large cats no fish!

30
Hierarchical Classification
There were 7 Levels of Biological Classification
when I learned them.

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

• Kids Playing Chicken On
• Freeways Get Squashed.

31
Linnaeus classification system has seven
levels.

• Each level is included in the level above it.

• Levels get increasingly specific from kingdom
  to species.

32
The Linnaean classification system has
limitations.

• Linnaeus taxonomy doesnt account for molecular
  evidence.
• The technology didnt exist during Linneaus
  time.
• Linnaean system based only on physical
  similarities.

33
Physical similarities are not always the result
of close relationships. Sometimes siiliarities
are due to environment
Genetic similarities more accurately show
evolutionary relationships.
34
How does it work?

• Each grouping is a taxon (pl. taxa) group of
  animals defined by a shared set of traits
• Every living thing that we know of fits into one
  of the six kingdoms
• Each level gets more specific as fewer
  organisms fit into each successive group (taxa)

35
Panthera leo
Felidae the Cat Family
Panthera pardus
Panthera tigris
Felis catus
Acinonyx jubatus
Lynx candensis
36
Checkpoint

• List the hierarchy of classification from kingdom
  to species.
• What is a taxon (plural taxa)?
• Are there more species in an order or in a class?

ANY QUESTIONS?
37
One Big Family?
Section 18-2
Interest Grabber

• How can you determine if one organism is closely
  related to another? It may seem easy, but it
  isnt, and looks are often deceiving. For
  example, roses and orchids are both flowering
  plants, but roses grow on bushes or vines and
  have thorns. Many orchids dont even grow in
  soilthey can grow in trees! Rose and orchid
  blossoms look very different, and roses and
  orchids cannot produce hybrids, or offspring of
  crosses between parents with different traits.

Go to Section
38
Section 18-2
Interest Grabber continued

• 1. Do you think roses and orchids are closely
  related? Explain your answer.
• 2. Now, apply the same logic to dogs. Different
  breeds of dogssuch as a Labrador retriever and a
  colliecan breed and produce offspring. So what
  is the difference between the rose-orchid
  combination and the Lab-collie combination?
• 3. What defines a species? Is appearance
  important? What other factors might be considered?

Go to Section
39
Section 18-2

• 182 Modern Evolutionary Classification
• A. Problems With Traditional Classification
• B. Evolutionary Classification
• C. Classification Using Cladograms
• D. Similarities in DNA and RNA
• E. Molecular Clocks

Go to Section
40
KEY CONCEPT Modern classification is based on
evolutionary relationships.
41

• Evolutionary Classification
• Classification based on lines of evolutionary
  descent or history.
• Derived characteristics
• Recent adapted characteristics not found in older
  members of the same descent line.
• Cladogram
• Diagram that shows evolutionary relationships
  among a group of organisms.
• Molecular Clock
• A model that shows how long two species have been
  evolving independently.

42
Cladistics is classification based on common
ancestry.

• Phylogeny is the evolutionary history for a
  group of species.
• evidence from living species, fossil record, and
  molecular data
• shown with branching tree diagrams

43

• Cladistics is a common method to make
  evolutionary trees.

• classification based on common ancestry
• species placed in order that they descended from
  common ancestor

44
DNA studies have shown that at the molecular
level many species show important
similarities. The genes allow scientists to
trace genetic history for an organism.
Classification Systems TODAY - Based on
SIMILARITIES that reflect Genetic RELATIONSHIPS
Scientists today use gt DNA sequencing gt Amino
acid sequencing gt Radioactive dating/fossil
record gt Similarities in embryological
development gt Homologous and vestigial structures
45
Evolutionary Classification

• Phylogeny study of how living and extinct
  organisms are related
• goal classify organisms according to common
  ancestry rather than similarities and differences
• Members of same genus share a more recent
  ancestor to each other than to other species in
  their order.
• The higher/larger the taxa, the farther back the
  common ancestor

46
Evolutionary Classification

• Clade taxa that include a single common
  ancestor and all of its descendents living or
  extinct
• Should include all species from that ancestor and
  exclude all species NOT from that ancestor
• Cladogram shows how species are related and
  branched over time according to shared derived
  characters
• Derived characters - traits passed to members in
  a given lineage homologous

47
Section 18-2
Traditional Classification Versus Cladogram
Appendages
Conical Shells
Crustaceans
Gastropod
Crab
Crab
Limpet
Limpet
Barnacle
Barnacle
Molted exoskeleton
Segmentation
Tiny free-swimming larva
TRADITIONAL CLASSIFICATION
CLADOGRAM
Go to Section
48
Section 18-2
Traditional Classification Versus Cladogram
Appendages
Conical Shells
Crustaceans
Gastropod
Crab
Crab
Limpet
Limpet
Barnacle
Barnacle
Molted exoskeleton
Segmentation
Tiny free-swimming larva
TRADITIONAL CLASSIFICATION
CLADOGRAM
Go to Section
49

• A cladogram is an evolutionary tree made using
  cladistics.

• A clade is a group of species that shares a
  common ancestor.

• Each species in a clade shares some traits with
  the ancestor.
• Each species in a clade has traits that have
  changed.

50
Derived characters are traits shared in
different degrees by clade members.

• basis of arranging species in cladogram
• more closely related species share more derived
  characters
• represented on cladogram as hash marks

51

• Nodes represent the most recent common ancestor
  of a clade.

FEATHERS AND TOOTHLESS BEAKS.

• Clades can be identified by snipping a branch
  under a node.

SKULL OPENINGS IN FRONT OF THE EYE AND IN THE JAW
OPENING IN THE SIDE OF THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
52
Molecular evidence reveals species
relatedness.

• Molecular data may confirm classification based
  on physical similarities.
• Molecular data may lead scientists to propose a
  new classification.

DNA is usually given the last word by scientists.
53
KEY CONCEPT Molecular clocks provide clues to
evolutionary history.
54
Molecular clocks use mutations to estimate
evolutionary time.

• Mutations add up at a constant rate in related
  species.
• This rate is the ticking of the molecular clock.
• As more time passes, there will be more mutations.

The DNA sequences from two descendant species
show mutations that have accumulated (black).
The mutation rate of this sequence equals one
mutation per ten million years.
DNA sequence from a hypothetical ancestor
55

• Scientists estimate mutation rates by linking
  molecular data and real time.

• an event known to separate species
• the first appearance of a species in fossil record

56
Mitochondrial DNA and ribosomal RNA provide two
types of molecular clocks.

• Different molecules have different mutation
  rates.
• higher rate, better for studying closely related
  species
• lower rate, better for studying distantly related
  species

57
Mitochondrial DNA is used to study closely
related species.

• mutation rate ten times faster than nuclear DNA
• passed down unshuffled from mother to offspring

58
Ribosomal RNA is used to study distantly
related species.

• many conservative regions
• lower mutation rate than most DNA

59
Dichotomous Keys

• Tool to determine the identity of an organism by
  going through a series of paired choices
• Dichotomous means "divided in two parts
• each alternative leads to another question until
  the item is identified
• Keys are identification tools do not propose
  an evolutionary history.

60
Cladogram- with shared derived characters
61
Where would you put a hairy, carnivorous animal
without retractable claws?
62
Cladogram
Where would you put an animal with claws but no
fur or feathers?
63
Are hyenas more closely related to dogs or cats?
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jpg

• What are two ways you could you find out?

64
My Way or the Highway
Section 18-3
Interest Grabber

• Categories that are used to organize an
  assortment of things should be valid. That is,
  they should be based on real information.
  However, categories should be useful, too.
  Suppose that you are taking a survey of traffic.
  You sit at the side of a busy intersection and
  record the vehicles you see in one hour.

Go to Section
65
Section 18-3
Interest Grabber continued

• 1. What categories could you use to organize
  your count of vehicles?
• 2. Look at your list of categories. Are all of
  them equally useful?
• 3. Is there more than one valid and useful way to
  organize living things?

Go to Section
66
Section 18-3

• Kingdoms and Domains
• A. The Tree of Life Evolves
• B. The Three-Domain System
• C. Domain Bacteria
• D. Domain Archaea
• E. Domain Eukarya
• 1. Protista
• 2. Fungi
• 3. Plantae
• 4. Animalia

Go to Section
67
Classification is always a work in progress.

• The tree of life shows our most current
  understanding.
• New discoveries can lead to changes in
  classification.
• Until 1866 only two kingdoms,Animalia and
  Plantae

68
Classification is always a work in progress.

• The tree of life shows our most current
  understanding.
• New discoveries can lead to changes in
  classification.
• Until 1866 only two kingdoms,Animalia and
  Plantae

Plantae
Animalia

• 1866 all single-celled organisms moved to
  kingdom Protista

69
Classification is always a work in progress.

• The tree of life shows our most current
  understanding.
• New discoveries can lead to changes in
  classification.
• Until 1866 only two kingdoms,Animalia and
  Plantae

• 1866 all single-celled organisms moved to
  kingdom Protista

• 1938 prokaryotes moved to kingdom Monera

70
Classification is always a work in progress.

• The tree of life shows our most current
  understanding.
• New discoveries can lead to changes in
  classification.
• Until 1866 only two kingdoms,Animalia and
  Plantae

• 1866 all single-celled organisms moved to
  kingdom Protista

• 1938 prokaryotes moved to kingdom Monera

• 1959 fungi moved to own kingdom

Monera
71
Classification is always a work in progress.

• The tree of life shows our most current
  understanding.
• New discoveries can lead to changes in
  classification.
• Until 1866 only two kingdoms,Animalia and
  Plantae

• 1866 all single-celled organisms moved to
  kingdom Protista

• 1938 prokaryotes moved to kingdom Monera

• 1959 fungi moved to own kingdom

• 1977 kingdom Monerasplit into kingdoms Bacteria
  and Archaea

72

• rRNA research by Carl Woese revealed two
  genetically
• Different groups of prokaryotes. This resulted
  in splitting the Kingdom Monera into two
  kingdoms Bacteria and Archea.
• His findings about the differences lead to the
  three domain system.

73
KEY CONCEPT The current tree of life has three
domains.
74
The three domains in the tree of life are
Bacteria, Archaea, and Eukarya.

• Domains are above the kingdom level.
• proposed by Carl Woese based on rRNA studies of
  prokaryotes
• domain model more clearly shows prokaryotic
  diversity

75
Domain Bacteria includes prokaryotes in the
kingdom Bacteria.

• one of largest groups on Earth
• classified by shape, need for oxygen, and
  diseases caused

76
Domain Archaea includes prokaryotes in the
kingdom Archaea.

• cell walls chemically different from bacteria
• differences discovered by studying RNA

• known for living in extreme environments

77
Domain Eukarya includes all eukaryotes.

• kingdom Protista

78
Domain Eukarya includes all eukaryotes.

• kingdom Protista

• kingdom Plantae

79
Domain Eukarya includes all eukaryotes.

• kingdom Protista

• kingdom Plantae

• kingdom Fungi

80
Domain Eukarya includes all eukaryotes.

• kingdom Protista

• kingdom Plantae

• kingdom Fungi

• kingdom Animalia

81
Kingdoms and Domains (underlined)
EUKARYA (eukaryotic one or more cells)
(extremophiles unique bacteria)
(true bacteria)
82
Hierarchical Classification
With Domains 8 levels

• Domain
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

• Dumb Kids Playing Chicken
• On Freeways Get Squashed.

83
Bacteria and archaea can be difficult to
classify.

• transfer genes among themselves outside of
  reproduction
• blurs the linebetween species
• more researchneeded tounderstand prokaryotes

84
Section 18-3
Concept Map
Living Things
are characterized by
Important characteristics
which place them in
and differing
Domain Eukarya
Cell wall structures
such as
which is subdivided into
which place them in
which coincides with
which coincides with
Go to Section
85
Section 18-3
Figure 18-12 Key Characteristics of Kingdoms and
Domains
Classification of Living Things
DOMAIN KINGDOM CELL TYPE CELL
STRUCTURES NUMBER OF CELLS MODE OF
NUTRITION EXAMPLES
Bacteria Eubacteria Prokaryote Cell walls with
peptidoglycan Unicellular Autotroph or
heterotroph Streptococcus, Escherichia coli
Archaea Archaebacteria Prokaryote Cell walls
without peptidoglycan Unicellular Autotroph
or heterotroph Methanogens, halophiles
Protista Eukaryote Cell walls of cellulose in
some some have chloroplasts Most unicellular
some colonial some multicellular Autotroph or
heterotroph Amoeba, Paramecium, slime molds,
giant kelp
Fungi Eukaryote Cell walls of
chitin Most multicellular some
unicellular Heterotroph Mushrooms, yeasts
Plantae Eukaryote Cell walls of cellulose
chloroplasts Multicellular Autotroph Mos
ses, ferns, flowering plants
Animalia Eukaryote No cell walls or
chloroplasts Multicellular Heterotroph
Sponges, worms, insects, fishes, mammals
Eukarya
Go to Section
86
Section 18-3
Figure 18-13 Cladogram of Six Kingdoms and Three
Domains
DOMAIN ARCHAEA
DOMAIN EUKARYA
Kingdoms
Eubacteria Archaebacteria Protista Plantae Fungi A
nimalia
DOMAIN BACTERIA
Go to Section
87

• What are the three domains of life?

88
Human Classification
Homework Complete a full classification list
for humans. Include the eight taxa in order and
name of each group that humans belong.
89
Full classification of human

• Domain Eukarya
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• Species sapien