1. Classification
Chapter 18

2. Taxonomy
Science of classifying organisms.

3. Why classify?
Over 10 million species on Earth

4. The problem with common names…
Mountain lion, puma, cougar or a panther.
Pill bug, doodle bug, roly poly
Common names vary among languages and even among regions, sometimes different species even can share the same common name.

5. Without using the name of the organism use as many terms as needed to describe the organism and it’s differences from other organisms.

6. Early efforts to classify
Described physical characteristics, sometimes over 20 words long for one name.
PROBLEM : different scientists describe organisms differently

7. Binomial Nomenclature
Set up by Carolus Linneaus – father of taxonomy, used physical characteristics to classify
Each species is given a 2 part name, the first word is capitalized and the second is lowercase, both are written in italics or underlined.
Ex. Homo sapien
Homo sapien
Say my name, say my name.

8. Scientific Names
Roar (loudly).
For a grizzly bear, Ursus is the genus name and arctos is the species name
Species names are unique to that individual group of organisms and are usually a description of an important trait or an indication of where that organism lives
Ursus maritimus, where does he live?
Maritim means to live near the sea
Common Name: Grizzly Bear
Scientific Name: Ursus arctos
Felis domesticus, cat what does “domesticus” mean?
Common Name: Polar Bear
Scientific Name: Ursus maritimus
Domesticus = “of the house”
Meow.

9. All bears are NOT alike- but they are all bears.
Scientific Names
All bears are NOT alike- but they are all bears.
Scientific Names of bears:
Common Name: Grizzly Bear
Scientific Name: Ursidae Ursus arctos
Common Name: Polar Bear
Scientific Name: Ursidae Ursus maritimus
Common Name: Black Bear
Scientific Name: Ursidae Ursus americanus
Common Name: Panda Bear
Scientific Name: Ursidae Ailuropoda melanoleuca
Common Name: Sloth Bear
Scientific Name: Ursidae Melursus ursinus

10. Linnaeus’s System of Classification
Linnaeus’s system is hierarchical, and includes 7 levels (largest to smallest), each level is called a taxon or taxa(plural).
Example: Humans
Kingdom
Animalia
Largest- plants, animals, insects, fish, bacteria- everything fits in here
Phylum
Chordata
King
Phillip
Came
Over
For
Good
Spagetti.
Yummy.
Class
Mammalia
Order
Primates
Family
Hominidae
Genus
Homo
Species
Smallest
sapiens

11. Bear Classification as an Example
Duh, it’s the fox.
Grizzly bear
Black bear
Giant panda
Red fox
Squirrel
Coral snake
Sea star
KINGDOM Animalia
Question:
Which organism is more closely related to the polar bear, the squirrel or the fox?
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos

12. Organisms are increasingly similar as you go from the level of kingdom to the level of species.
Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora

13. Family Canidae (canine)

14. Genus Canis

15. Are these dogs the same species?

16. YES!
Remember the definition for species? Group of similar organisms that can breed and produce fertile offspring.
horse + donkey = mule (non-fertile offspring)
species + species = non-species
All dogs are given the species name Canis familiaris, the differences seen are called breeds.

17. Similarities in DNA and RNA
Most classification methods are based on physical similarities and differences.
However the genes of many organisms show important similarities at the molecular level.
These similarities can help classify organisms and figure out their evolutionary relationships.

18. Similarities in DNA and RNA
Most classification methods are based on physical similarities and differences.
genes of many organisms show important similarities at the molecular level.
These similarities can help classify organisms and figure out their evolutionary relationships.
Storks
American vulture
Falcon
African Vulture

19. Molecular Clocks
DNA comparisons can also be used to mark the passage of evolutionary time
Molecular Clock model uses DNA comparisons to estimate the length of time that 2 species have been evolving independently
Looks for mutations that separate 2 species
Other changes in DNA
Compares DNA sequences between species
Which organisms are more closely related?
Why?
Human:   CCA TAG CAC CTA
Pig:   CCA TGG AAA CGA
Chimpanzee:   CCA TAA CAC CTA
Cricket:   CCT AAA GGG ACG
Only 1 mutation separates human and chimp in this portion of the gene

20. Evolutionary Classification
Barnacles
Crab
Crustaceans
Gastropods
Actually, crabs and barnacles are more closely related evolutionarily.
Limpet
Crab
Barnacle
Limpet
Box 13
This branching shows that crabs and barnacles share a more recent common ancestor.
CLADOGRAM
Molted exoskeleton
Derived characteristics in crustaceans =
-Segmented bodies
-Hard external skeleton shed during growth
Tiny free-swimming larva
Cladogram = shows the evolutionary relationships among a group of organisms
Box 14

21. Classification today Developed by Whittaker, contains the 5 kingdoms
Greatest division is no longer between plants and animals but rather prokaryotes and eukaryotes
The three “higher” kingdoms are distinguished by their ecological strategies:
absorption (FUNGI), consumption (ANIMALIA) and production (PLANTS)

22. Kingdoms and Domains Tree of Life
Sec. 18-3
In Linnaeus’s time, life was much simpler. Either you were a plant or an animal.
Today, classification is more complicated.
Protists? Bacteria? Viruses?
Tree of Life (
Life is full of Diversity
Robert Hooke and Van Leewenhoek – showed us the microscopic world, bacteria, protists, microorganisms
Discovering all these microscopic life forms, added branches to the Tree of Life
Tree of Life

23. The Five Kingdoms Kingdom Monera Kingdom Protista Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
** Some scientists argue that there are 6 kingdoms, they divide Kingdom Monera (bacteria) into 2 separate kingdoms known as Kingdom Archaebacteria and Kingdom Eubacteria.

25. Then what on Earth is a Domain?
A new taxonomic category that is larger than a kingdom.
3 total
1. Domain Eukarya – protists, fungi,plants and animals
2. Domain Archaebacteria
3. Domain Eubacteria

26. Domain Bacteria Unicellular Prokaryotic Cell walls are rigid and thick
Corresponds with the kingdom eubacteria
Autotrophs and heterotrophs

27. Domain Archaea Unicellular Prokaryotic
Live in extreme environments such as sulfur springs, salt lakes
Most are anaerobic
Cell walls lack peptidoglycan, cell membranes contain unusual lipids not found in any other organisms
Corresponds with the kingdom archaebacteria
Examples include methanogens, bacteria that get their energy from methane gas
Methanogens (methane-producers)--responsible for swamp gas and…
Extreme Thermophiles--live in hot springs and black smokers.
Owen’s Lake, NV
Yellowsprings
Yellowstone Park
3. Extreme Halophiles--live in saturated brine and salt crust.

28. Domain Eukarya Eukaryotic Uni and multicellular Auto or heterotrophs
Some are photosynthetic (plants)
Contains 4 kingdoms, plantae, animalia, fungi and protista

29. Kingdom Monera Includes all types of bacteria – archaic and true
Some microbes live on our skin and protect us from many harmful agents. The drier areas, like the back, have few microbes; moist areas, such as under the arm, have many more.
Escherichia coli (a.k.a. E. coli) lives in the gut, where it helps digest food
Staphylococcus (a.k.a. staph) can cause serious infections and is one of the most drug-resistant bacteria
Lactobacillus bulgaricus helps turn milk into cheese, yogurt, and other dairy products. Lactose intolerant anyone?
Bacteria on a contact lens

30. Kingdom Protista 200,000 species
Any organism that is not a plant, animal, fungus or prokaryote
Eukaryotes
Most are unicellular but there are some multicellular
Animal-like protists are considered heterotrophs
Plant-like protists are considered autotrophs
Algae, euglena, paramecium, ameoba, slime molds

31. Examples of Protists
Figure 2: Some examples of marine protists, all of which about 100 micrometers in diameter or length They fall within the size-category of the microplankton. (A) a diatom an autrophic protist, (B) a herbivorous oligotrich ciliate, (C) a herbivorous tintinnid ciliate, (D) a dinoflagellate, and (E) a radiolarian. Images by J.R. Dolan

32. Kingdom Fungi Mushrooms, molds, yeast Many grow from ground
Eukaryotic heterotrophs that have cell walls made of chitin, also found in the tough outer covering of insects.
Many feed off of decaying soil, some are parasites, secrete enzymes that digest and then absorb (not eat) the smaller food molecules
Some produce sexually, some asexually

33. Examples of Fungi

34. Kingdom Plantae Photosynthetic, autotrophic, eukaryotes
Cell walls made of cellulose
Nonmotile

35. Kingdom Animalia Heterotrophic, multicellular, eurkayotes
No cell walls
Sponges, worms, fish, insects, mammals

36. Animalia The Kingdom Animalia is divided into 6 phyla:
1. Sponges and Cnidarians
2. Mollusks
3. Worms
4. Arthropods
5. Echinoderms
6. Verterbrates

37. 1. Sponges and Cnidarians
The only animals that
do not have tissues.
Mostly marine.
Ex. Jellyfish, corals

38. 2. Mollusks
Have something called a coulomb (sac-like structure) that encloses their internal organs.
Most have a hard external skeleton (shell).
Ex. Snails, oysters, clams, octopuses

39. 2. Mollusks

40. 3. Worms
Cylinder shaped bodies.
Live on both land and water.

41. 4. Arthropods Most diverse of all animals. Have an external skeleton.
Have jointed appendages, such as antennae and jaws.
High rate of reproduction.
2/3 of all animals.

42. 4. Arthropods

43. 5. Echinoderms Ability to regenerate a lost limb.
Ex. Sea stars, sea urchins

44. 6. Verterbrates Internal skeleton made of bone.
Includes mammals, fish, birds, reptiles and amphibians.

45. Warm Up #1 on a blank sheet of paper
What is taxonomy?
What scientist developed the classification system we use today?
List all seven taxa in order from SMALLEST to LARGEST.
Which taxon contains more organisms; a family or a class?

46. Did you know…
Oysters change their sex several times over their lifetime.

47. Warm Up #2
Name a few problems with early classification efforts.

48. Did you know
If you could drive your car straight up you would arrive in space in just over an hour.

49. Warm Up #3
For the vocabulary words below, state the major difference between the words and give an example for each word.
autotroph/heterotroph
Prokaryote/eukaryote
Unicellular/multicellular
Anaerobic/aerobic

50. Female black widow spiders eat their males after mating.

51. Warm Up #4 How many domains are there?
Which is larger a kingdom or a domain?
If two organisms are in the same family, list all of the other taxa they are also classified in together.

53. Kingdoms DOMAIN EUKARYA DOMAIN ARCHAEA Eubacteria Archaebacteria
Protista
Plantae
Fungi
Animalia