1. Classification
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2. The Challenge
Biologists have identified and named approximately 1.5 million species so far.
They estimate that between 2 and 100 million species have yet to be identified.

3. Finding Order in Diversity
1. Why Classify?
To study the diversity of life
To organize and name organisms
2. Why give scientific names?
Common names are misleading
jellyfish
silverfish
star fish
None of these animals are fish!
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4. Why Scientists Assign Scientific Names to Organisms
Some organisms have several common names
This cat is commonly known as:
Florida panther
Mountain lion
Puma
Cougar
Scientific name: Felis concolor
Scientific name means “coat of one color”
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5. Origin of Scientific Names
By the 18th century, scientists realized that naming organisms with common names was confusing.
Scientists during this time agreed to use a single name for each species.
They used Latin and Greek languages for scientific names.

6. Linnaeus: The Father of Modern Taxonomy
1732: Carolus Linnaeus developed system of classification – binomial nomenclature
Two name naming system
Gave organisms 2 names
Genus (noun) and species (adjective)
Rules for naming organisms
1. Written is Latin (unchanging)
2. Genus capitalized, species lowercase
3. Both names are italicized or underlined
EX: Homo sapiens: wise / thinking man
Carolus Linnaeus
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7. 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

8. Linnaeus’s System of Hierarchy
Least specific
Kingdom
Which of the following contains all of the others?
Family c. Class
Species d. Order
Based on their names, you know that the baboons Papio annubis and Papio cynocephalus do not belong to the same:
Family c. Order
Genus d. Species
Phylum
Class
Order
Family
Genus
Most specific
Species
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9. Modern classification is based on evolutionary relationships.

10. Modern Classification
Linnaeus grouped species into larger taxa, such as genus and family, based on visible similarities.
Darwin’s ideas about descent with modification evolved into the study of phylogeny, or evolutionary relationships among organisms.

11. How do we classify? Structural (anatomy and physiology)
Biochemical (enzymes, proteins, DNA)
Cytological (cell structure)
Embryological (development)
Behavioral (patterns of actions)
Fossil (common ancestor)

12. Modern Classification
Modern biologists group organisms into categories representing lines of evolutionary descent.
Species within a genus are more closely related to each other than to species in another genus.
Genus: Felis
Genus: Canis

13. Similarities in DNA and RNA
Scientists use similarities and differences in DNA to determine classification and evolutionary relationships.
They can sequence or “read” the information coded in DNA to compare organisms.

14. 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

15. Cladistics is a method to make evolutionary trees.
classification based on common ancestry
species placed in order that they descended from common ancestor

16. 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.

17. basis of arranging species in cladogram
Derived characters are traits shared in different degrees by clade members.
FOUR LIMBS WITH DIGITS
Tetrapoda clade 1
Amniota clade 2
Reptilia clade 3
Diapsida clade 4
Archosauria clade 5
EMBRYO PROTECTED BY AMNIOTIC FLUID
OPENING IN THE SIDE OF THE SKULL
SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW
FEATHERS & TOOTHLESS BEAKS.
SKULL OPENINGS BEHIND THE EYE
DERIVED CHARACTER
basis of arranging species in cladogram
more closely related species share more derived characters
represented on cladogram as hash marks

18. Nodes represent the most recent common ancestor of a clade.
FOUR LIMBS WITH DIGITS
CLADE
Tetrapoda clade 1
Amniota clade 2
Nodes represent the most recent common ancestor of a clade.
Reptilia clade 3
Diapsida clade 4
Archosauria clade 5
FEATHERS AND TOOTHLESS BEAKS.
SKULL OPENINGS IN FRONT OF THE EYE AND IN THE JAW
Clades can be identified by snipping a branch under a node.
OPENING IN THE SIDE OF THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
DERIVED CHARACTER
NODE

19. 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.

20. Molecular clocks provide clues to evolutionary history.

21. 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.
Mutations add up at a fairly
constant rate in the DNA of species that evolved from a common ancestor.
Ten million years later—
one mutation in each lineage
Another ten million years later—
one more mutation in each lineage
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

22. 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

23. Ribosomal RNA is used to study distantly related species
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
Ribosomal RNA is used to study distantly related species
many conservative regions
lower mutation rate than most DNA

24. Mitochondrial DNA is used to study closely related species.
mutation rate ten times faster than nuclear DNA
passed down unshuffled from mother to offspring
grandparents
parents
child
Nuclear DNA is inherited from both
parents, making it more difficult to
trace back through generations.
Mitochondrial DNA is
passed down only from
the mother of each generation,so it is not subject to recombination.
mitochondrial
DNA
nuclear DNA

25. Kingdoms and Domains
In the 18th century, Linnaeus originally proposed two kingdoms: Animalia and Plantae.
By the 1950s, scientists expanded the kingdom system to include five kingdoms.

26. The Five Kingdom System

27. The Six Kingdom System
In recent years, biologists have recognized that the Monera are composed of two distinct groups.
As a result, the kingdom Monera has now been separated into two kingdoms: Eubacteria and Archaebacteria, resulting in a six-kingdom system of classification.

28. The Three-Domain System
Scientists can group modern organisms by comparing ribosomal RNA to determine how long they have been evolving independently.
This type of molecular analysis has resulted in a new taxonomic category—the domain.

29. The Three Domains
The three domains, which are larger than the kingdoms, are the following:
Eukarya – protists, fungi, plants and animals
Bacteria – which corresponds to the kingdom Eubacteria.
Archaea – which corresponds to the kingdom Archaebacteria.

30. The three domains in the tree of life
Domains are above the kingdom level.
proposed by Carl Woese based on rRNA studies of prokaryotes
domain model more clearly shows prokaryotic diversity

31. Classification of Living Things
The three-domain system
Bacteria
Archaea
Eukarya
The six-kingdom system
Eubacteria
Archae-
bacteria
Protista
Plantae
Fungi
Animalia

32. Each level is more specific.
Hierarchical Ordering of Classification
Grizzly bear
Black bear
Giant panda
Red fox
Abert squirrel
Coral snake
Sea star
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
As we move from the kingdom level to the species level, more and more members are removed.
Each level is more specific.
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
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33. Kingdom Archaebacteria
Cell Type
Prokaryote
Number of Cells
Unicellular
Nutrition
Autotroph or Heterotroph
Location
Extreme Environments Volcanoes, Deep Sea Vents, Yellowstone Hot Springs
Examples
Methanogens
Thermophiles
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34. Kingdom Eubacteria Cell Type Prokaryote Number of Cells Unicellular
Nutrition
Autotroph or Heterotroph
Examples
Streptococcus, Escherichia coli (E. coli)
E. coli
Streptococcus
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35. The “Junk-Drawer” Kingdom
Kingdom Protista
Cell Type
Eukaryote
Number of Cells
Most Unicellular, some multicellular
Nutrition
Autotroph or Heterotroph
Examples
Amoeba, Paramecium, Euglena,
Paramecium
Green algae
The “Junk-Drawer” Kingdom
Amoeba
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36. Most Fungi are DECOMPOSERS
Kingdom Fungi
Cell Type
Eukaryote
Number of Cells
Most multicelluar, some unicelluar
Nutrition
Heterotroph
Example
Mushroom, yeast, mildew, mold
Mildew on Leaf
Most Fungi are DECOMPOSERS
Mushroom
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37. Kingdom Plantae Cell Type Eukaryote Number of Cells Multicellular
Ferns : seedless vascular
Cell Type
Eukaryote
Number of Cells
Multicellular
Nutrition
Autotroph
Examples
Mosses, ferns, conifers, flowering plants
Douglas fir: seeds in cones
Sunflowers: seeds in flowers
Mosses growing on trees
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38. Kingdom Animalia Cell Type Eukaryote Number of Cells Multicellular
Nutrition
Heterotroph
Examples
Sponges, worms, insects, fish, mammals
Bumble bee
Jellyfish
Sage grouse
Hydra
Poison dart frog
Sponge
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39. Dichotomous Key
Tool used by biologists to identify an unknown organism
Series of paired statements of anatomical description that leads to an identification.

40. What bird am I ?

41. Key for Vertebrate Identification
What am I ???
1. a) animal has a spine…………………..go to 2
b) animal has no spine………..…invertebrate
2. a) animal has no gills and fins……..…. go to 3
b) animal has gills and fins…………….. Fish
3. a) animal has no scales………… go to 4
b) animal has scales………………..….reptile
4. a) animal has feathers …………………..bird
b) animal has no feathers ……………..go to 5
5. a) animal has hair…………………….mammal
b) animal has no hair………………..amphibian