1. Chapter 17 Classification
Information from Holt Biology & other sites as listed

2. Are you an organized person?
Consider – do you organize your room? CDs?
Your clothes? Your school work?
What would happen if nothing was organized?
Would you be able to find anything?
Why is it necessary to classify?

3. *Scientists have identified more than
2 MILLION SPECIES OF ORGANISMS- But estimate 40 MILLION SPECIES inhabit the Earth.
*There may be millions of undiscovered species, especially microbes, plants & insects , In the Tropical Rain Forest & Oceans
*Every year, thousands of new species are discovered.

4. I. Biodiversity Biodiversity is the variety of organisms on the earth.
Considered at all levels from populations to ecosystems.
Naturalists have invented several systems for categorizing

5. A. Taxonomy
Taxonomy is the science of describing, naming, and classifying organisms.
The branch of biology that names & groups organisms -according to their characteristics & evolutionary history.
A Universal System was designed to Eliminate the use of Common Names and Confusion in the Scientific World.

6. History of Taxonomy a. Aristotle –Early Classification system
Greek philosopher more than 2,000 years ago
Classified things- Plant or Animal
Grouped Animals into Land Dwellers, Water Dwellers, and Air Dwellers.
Also grouped Plants into 3 categories, based on differences in their Stems.

7. Naturalists replaced Aristotle’s classification system
As modern science developed in the fifteenth and sixteenth centuries, Aristotle's system was found to be
INADEQUATE.
Aristotle's categories
did not work for
all organisms.
his use of common names
was problematic.

8. Use of Common Names Use of long Latin names
COMMON NAMES, such as “robin” or “fir tree”, for organisms created some problems
common names varied from one locale to next & did not describe species accurately.
Use of long Latin names
Used by scientists before 1700’s,- did not show relationships between species & were inconvenient, hard to understand.

9. Describe a problem with each of these common names
-Starfish -Seahorse -Jelly fish
-Peanut -Catfish -Tiger shark
How are their names misleading?
Discuss problems when 1 organism has 2 common names
Example- firefly & lightening bug

10. b. Carl Linnaeus (1707-1778) “Father of Modern Taxonomy”
Swedish Naturalist
Used morphology
(structure & form)
Grouped organisms
into hierarchical categories

11. Linnaeus Formed “Taxa” (groups of organisms)
(Used Latin for the Names because it was the language of educated people)
System was based on Morphology which are the STRUCTURAL SIMILARITIES BETWEEN ORGANISMS
Series of hierarchical categories used to show relationships

12. Linneaus divided organisms into 2 KINGDOMS: PLANTAE & ANIMALIA.
Then divided each Kingdom into smaller groups.
(Linnaeus's classification hierarchy had 5 levels)
KINGDOM, CLASS, ORDER, GENUS, SPECIES
EACH LEVEL GROUPS TOGETHER ORGANISMS THAT SHARE MORE CHARACTERISTICS WITH EACH OTHER. (general to more specific)
Modern scientists add 2 more classifications levels to original 5: PHYLUM & FAMILY.

13. 7 Modern Levels of Classification (From the most general to the most specific)
Kingdom
Phylum
Class
Order
Family
Genus
Species
Species is the smallest, most specific.
Categories get larger, more general.
Kingdom is the largest, least specific

14. Pneumonic Devices Keep Penguins Cool Or Find Good Shelter
Kennywood Park Can Open For Good Summers.
King Phillip Comes Over For Good Spaghetti

16. Classification Hierarchy of Organisms

17. 3 Domains: Archaea Bacteria Eukarya Most modern system by Carl Woese
These are Broad groups above the kingdom level.
Archaea
Bacteria
Eukarya

18. 2. Binomial Nomenclature
“Two name naming”
Uses the last 2 categories (the most specific) to name things.
Developed by Carl Linnaeus using the hierarchical system- uses the Genus & Species for the 2 parts of the name
Always Capitalize the Genus but Not the Species Identifier. Both are either underlined or italicized.

19. Using Binomial Nomenclature
Acer rubrum - RED MAPLE TREE
  Acer is the Latin name for Maple (genus)
  rubrum is the Latin word for Red(species)
  Can be Abreviated: A.rubrum.
HUMANS ARE NAMED: Homo sapiens
Homo -large brain & upright posture. sapiens for our intelligence & ability
to speak Abbreviated H. sapiens

20. Additional Categories
Zoologists-use term “SUBSPECIES” for variations that may occur in species from different geographical locations- ie, timber wolf and the northern timber wolf-
Canis Lupus ssp occidentalis
Botanists
May use the term “division” instead of phylum
sometimes split species into Subsets known as VARIETIES. Example: peaches & nectarines are varieties of Prunus persica var.

21. Microbiologists- Bacteria are also broken into subsets called STRAINS
Microbiologists- Bacteria are also broken into subsets called STRAINS. Example: Escherichia Coli – some strains are harmless, even helpful;- live in our intestines, but strain E. coli is responsible for food poisoning deaths.
According to the CDC there are an estimated 73,000 cases of E. Coli infection every year in the United States. The typical symptoms are bloody diarrhea and (if severe) kidney failure. These symptoms most commonly appear when a person has eaten undercooked or contaminated ground beef.

22. II. Systematics
  *The way we group organisms continues to change, and today these methods reflect the evolutionary history of organisms (What’s in their genes). This is called Phylogeny.

23. Systematics
* organizes the diversity of living organisms in the context of evolution.
Scientists construct Phylogenic Trees based on several types of evidence:
Fossil Record 2. Morphology
Embryology
Chromosomes & Macromolecules

24. 1. Phylogenic Trees
A family tree that shows evolutionary relationships thought to exist among organisms.
Is a hypothesis about the relationships.
Is subject to change - as more evidence is learned.

27. 1. Fossil Record Fossil Record a useful tool for ancient organisms.
II. Shared ancestry: Evidences for Evolutionary Relationships
1. Fossil Record
Fossil Record a useful tool for ancient organisms.
Record is incomplete
Some organisms overrepresented
Some organisms may be missing
Need other evidences to verify phylogenic relationships

28. Fossils Types: actual preservation, petrification, imprints, molds, casts, footprints
Dated by radioactive isotopes in fossil or geological formation in which fossils are found
Requires long periods
of time and unusual conditions for fossil preservation

29. II. Shared ancestry: Evidences for Evolutionary Relationships
2. Morphology
Examine structure & function
Homologous structures- similar features that originated from similar ancestors. (forelimbs on bat, human, penguin)
Analogous structures- features that serve similar functions & look alike but originated from different embryonic tissues.
(wings- on butterfly, bat, hummingbird)

30. Homologous structures
Comparing the structural features found in different organisms reveals a basic similarity.
example is the forelimb of mammals - Although function is quite different, they are similar structurally.

31. Analogous structures
We must look at structures that look & function the same but are not derived from the same embryonic tissue.
These features do not show recent, related ancestory.

32. Vestigial structures
Features which serve no useful function any longer in the organism.
Examples: the pelvis bone in the whale, tailbone & appendix in humans, pelvis & leg bones in some snakes, etc

33. II. Shared ancestry: Evidences for Evolutionary Relationships
Embryology
SIMILARITIES IN EARLY EMBRYOLOGICAL DEVELOPEMNT OF VERTEBRATES CAN BE TAKEN AS ANOTHER INDICATION THAT VERTEBRATES MAY SHARE A COMMON ANCESTRY.

34. At the blastula stage, scientists begin to look for differences in the ways organisms develop.

35. Blastula - An early embryonic form produced by cleavage of a fertilized ovum - a spherical layer of cells surrounding a fluid-filled cavity.(think of a basketball) Gastrula - double-walled stage of the embryo succeeding the blastula; the outer layer of cells is the ectoderm and the inner layer differentiates into the mesoderm and endoderm

36. Conclusion- we are more closely related to starfish than insects
Embryology example-
At the blastula stage- what happens if a scientist separates a cell from the ball?
In Vertebrates (animals with a backbone) & Echinoderms animals like starfish & sand dollars)- any cell separated can produce a “twin”.
But blastula cells in a fruit fly cannot- the separated cells are already specialized to form a part & will die.
Conclusion- we are more closely related to starfish than insects

37. 4. Chromosomes & Macromolecules
II. Shared ancestry: Evidences for Evolutionary Relationships
4. Chromosomes & Macromolecules
Taxonomists compare Macromolecules like DNA, RNA & Proteins.
Example- the number of differences in amino acids is a clue to how long ago 2 species “Diverged”
In Divergent Evolution- 2 species become more and more dissimilar.
Convergent Evolution- Species which have different ancestors, but have become more similar

38. # of amino acids different
Proteins indicate degree of relatedness. Differences - Amino Acids in Protein Cytochrome C
(From Atlas of Protein Sequence and Structure, by Margaret O. Dayhoff
Number of different amino acids found in human cytochrome C as opposed to selected organisms
 Organism
# of amino acids different
compared to humans
Human
Self (Family Hominidae, Order Primates)
Monkey 1
Different family (Pongidae), same order (Primates)
Pig, bovine, sheep 10
Different order (Carnivora), same class (Mammalia)
Horse 12
Dog 11
Rabbit 9
Chicken, Turkey 13
Different class (Aves), same phylum (Chordata) - homeothermic
Duck
Rattlesnake 14
Different class (Reptilia), same phylum (Chordata) - poikilothermic
Turtle 15
Tuna 21
Different class (Ostheichthys), same phylum (Chordata) - poikilothermic
Moth 31
Different phylum (Arthropoda), same Kingdom (Animalia)
Candida fungus 51
Different Kingdom (Fungi)

39. Martin (1993).

40. B. Cladistics
uses shared, derived characters as the only criterion for grouping taxa.
is a newer way to display relationships which highlights other differences (shared or derived chracters)

41. Shared characters-
Derived Characters- are special features that apparently have only developed in that group
– like feathers in birds

42. Cladogram
Shared derived characters are strong indicators of common ancestry.
Diagrams which show derived characters are called cladograms.
Cladograms can show non-traditional conclusions about
which organisms
are “close cousins”.

43. From this cladogram, we can figure out that brown bears have more derived characters in common with sun bears than with dogs & lesser pandas are more closely related to racoons than giant pandas.

44. Cladogram

45. Dichotomous Key
A dichotomous key graphically organizes data. You start with a main idea, split that into two major pieces. Those pieces are then split again into two major pieces. You can continue splitting each piece until you reach only one possible answer.
Each set of questions is called a couplet, & contains instructions for which couplet to go to next.

46. Example of Dichotomous Key

47. Dichotomous Key Use Can be used by any one to classify anything.
Are used by taxonomists to classify organisms.

48. III. TWO MODERN SYSTEMS OF CLASSIFICATION
 Aristotle classified organisms as either plant or animal, but today we recognize that many forms of life are neither
2 Ways to organize (things continue to change)
Three Domain System
Six Kingdom System

49. Autotroph- Makes own food (photosysthesis or chemosynthesis)
Modern TAXONOMY recognizes that many organisms are Neither Plant or Animal.
Study cellular structure
Look at ways organisms obtain food:
Autotroph- Makes own food (photosysthesis or chemosynthesis)
Heterotroph- Eats something

50. 3 Domain System Archaea Bacteria Eukarya
Compares Ribosomal RNA of different organisms.
Most modern system by Carl Woese
Broad groups
Archaea
Bacteria
Eukarya

51. 3 Domains Archaea = Prokaryotic cells Bactaeria = Prokaryotic cells
3. Eukarya = Eukaryotic cells
There are four kingdoms in Eukarya
* Protista * Fungi
* Plantae * Animalia

53. SIX KINGDOMS GROUP ORGANISMS TOGETHER THAT HAVE SIMILARITIES SUCH AS MAJOR CELLULAR STRUCTURE, METHODS OF OBTAINING NUTRIENTS, AND METABOLISM.

54. The 3 Domains in detail: Domain Archaea Domain Bacteria Domain Eukarya
aligns with Kingdom Archaebacteria, are single-celled prokaryotes that have distinctive cell membranes and cell walls.
Domain Bacteria
aligns with Kingdom Eubacteria, are single-celled prokaryotes that are true bacteria.
Domain Eukarya
Domain Eukarya includes the kingdoms Protista, Fungi, Plantae, and Animalia.
All members of this domain have eukaryotic cells.

55. Domain: Archaea & Bacteria
What are Bacteria?
Until recently, the term bacteria was used for all microscopic prokaryotes. But, it turns out that there are two groups of prokaryotes that differ from each other in just about every way except size and lack of a nucleus.
These are now divided into 2 kingdoms:
Archaea -(also known as Archaebacteria) anicient, extreme environments.
Bacteria- the "true" bacteria (also known as Eubacteria)

56. Domain: Archaea & Bacteria
Organisms in the Kingdoms Eubacteria & Archae are very different from each other.
Archaebacteria have been found in temperatures above the boiling point and in cold that would freeze your blood. Eubacteria are the “regular” bacteria.

57. Domain: Archaea, Kingdom Archeabacteria
The prefix archae - comes from the Greek Word "ANCIENT".  MAY BE Directly descended from and very similar to the First Organisms on Earth. 
They Are UNICELLULAR PROKARYOTES with distinctive Cell Membranes as well as Biochemical and Genetic Properties that Differ from ALL Other Kinds of Life. 
Some are AUTOTROPHIC, producing food by CHEMOSYNTHESIS. Most are HETEROTROPHIC. 

58. Some types are A. Methanogens B. Themoacidophiles
Domain: Archaea, Kingdom Archaeabacteria
Archaea:
Some types are
A. Methanogens
B. Themoacidophiles
C. Extreme Halophiles

59. Domain: Archaea, Kingdom Archaeabacteria
Called Extremophiles
Many Archaebacteria LIVE in HARSH ENVIRONMENTS such as Sulfurous Hot Springs, Very Salty Lakes, and in ANAEROBIC Environments, such as the Intestines of Mammals. Includes Chemosynthetic Bacteria.

60. Domain: Bacteria, Kingdom Bacteria
The “true” bacteria
The first thing you probably think of when you say this word is “disease”- something like strep. throat or maybe an infection in a cut.
Most of the bacteria that are disease causing are Eubacteria.
NOTE: Only about 1% of bacteria are disease causing.

61. Many bacteria are very helpful organisms.
Domain: Bacteria, Kingdom Bacteria
Many bacteria are very helpful organisms.
Actinomycetes, produce antibiotics such as streptomycin and nocardicin;
others live symbiotically in the guts of animals (including humans) or elsewhere in their bodies, or on the roots of certain plants, converting nitrogen into a usable form.
Bacteria put the tang in yogurt and the sour in sourdough bread;
help to break down dead organic matter; & make up the base of the food web in many environments.

62. The true or “Eubacteria”
Domain: Bacteria, Kingdom Bacteria
The true or “Eubacteria”
UNICELLULAR PROKARYOTES (No true nucleus)
Are the greatest number of living things on earth.
No membrane bound organelles
Circular double strand of DNA
“Eu” means true. Eubacteria are the common, true bacteria- causing strep throat, food poisioning, tooth decay, fermenting milk into yogurt, etc.

63. Classifying bacteria:
Domain: Bacteria, Kingdom Bacteria
Classifying bacteria:
Bacteria occur in 3 basic shapes: cocci, bacilli & spiral. Many are named by their shape.

64. 3. Protists EUKARYOTIC (has a true, membrane bound nucleus)
Domain: Eukarya, Kingdom Protista
3. Protists
Made of a variety of organisms that don’t “fit” anywhere else. Some are not very much like the others in this group.
EUKARYOTIC (has a true, membrane bound nucleus)
50,000 species- many unicellular, some are like fungi, some like plants or animals.
Includes protozoans, unicellular algae, slime molds & water molds

65. Protists includes slime molds & protozoans like Euglena, Paramecium, Ameoba

66. 4. Fungi Unicellular & multicellular
Domain: Eukarya, Kingdom Fungi
4. Fungi
Unicellular & multicellular
HETEROTROPHIC (eats something else)
NOT like plants (photosyntheic)
100,000 species include mushrooms, puffballs, rusts, mildew & molds

67. Domain: Eukarya, Kingdom Plantae
Multicellular & Photosynthetic Autotrophs (food by photosynthesis) They are the chief producers of the world.
Found in all the types of environments: aquatic algae, amphibian mosses, and terrestrial ferns and seed-bearing plants.
350,000 species identified.

69. 6. Animalia Eukaryotic, Multicellular Heterotrophic organisms.
Domain: Eukarya, Kingdom Animalia
6. Animalia
Eukaryotic, Multicellular Heterotrophic organisms.
Most animals are symmetrical
Movement at some time in their life cycle.