Classification

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Classification

• Chapter 18

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Taxonomy

• Science of classifying organisms.

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Why classify?

• Over 10 million species on Earth

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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.
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• Without using the name of the organism use as
  many terms as needed to describe the organism and
  its differences from other organisms.

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Early efforts to classify

• Described physical characteristics, sometimes
  over 20 words long for one name.
• PROBLEM different scientists describe
  organisms differently

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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.
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Scientific Names
Roar (loudly).

• For a grizzly bear, Ursus is the genus nameand
  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, catwhat does domesticus mean?
Common Name Polar Bear Scientific Name Ursus
maritimus
Domesticus of the house
Meow.
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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
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Linnaeuss System of Classification

• Linnaeuss 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
Hominidae
Family
Genus
Homo
Species Smallest
sapiens
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Bear Classification as an Example
Duh, its 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
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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

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Family Canidae (canine)
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Genus Canis
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Are these dogs the same species?
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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.

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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.

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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
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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
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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
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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)

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Kingdoms and Domains
Sec. 18-3

• In Linnaeuss time, life was much simpler.
  Either you were a plant or an animal.
• Today, classification is more complicated.
• Protists? Bacteria? Viruses?
• Tree of Life (www.tolweb.org)
• 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

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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.

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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

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Domain Bacteria

• Unicellular
• Prokaryotic
• Cell walls are rigid and thick
• Corresponds with the kingdom eubacteria
• Autotrophs and heterotrophs

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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.

Owens Lake, NV
Yellowsprings Yellowstone Park
3. Extreme Halophiles--live in saturated brine
and salt crust.
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Domain Eukarya

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

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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
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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

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Examples of Protists
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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

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Examples of Fungi
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Kingdom Plantae

• Photosynthetic, autotrophic, eukaryotes
• Cell walls made of cellulose
• Nonmotile

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Kingdom Animalia

• Heterotrophic, multicellular, eurkayotes
• No cell walls
• Sponges, worms, fish, insects, mammals

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Animalia

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

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1. Sponges and Cnidarians

• The only animals that
• do not have tissues.
• Mostly marine.
• Ex. Jellyfish, corals

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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

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2. Mollusks
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3. Worms

• Cylinder shaped bodies.
• Live on both land and water.

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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.

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4. Arthropods
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5. Echinoderms

• Ability to regenerate a lost limb.
• Ex. Sea stars, sea urchins

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6. Verterbrates

• Internal skeleton made of bone.
• Includes mammals, fish, birds, reptiles and
  amphibians.

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Warm Up 1 on a blank sheet of paper

1. What is taxonomy?
2. What scientist developed the classification
   system we use today?
3. List all seven taxa in order from SMALLEST to
   LARGEST.
4. Which taxon contains more organisms a family or
   a class?

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Did you know

• Oysters change their sex several times over their
  lifetime.

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Warm Up 2

• Name a few problems with early classification
  efforts.

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Did you know

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

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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

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• Female black widow spiders eat their males after
  mating.

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Warm Up 4

1. How many domains are there?
2. Which is larger a kingdom or a domain?
3. If two organisms are in the same family, list all
   of the other taxa they are also classified in
   together.

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DOMAIN EUKARYA
DOMAIN ARCHAEA
Kingdoms
Eubacteria Archaebacteria Protista Plantae Fungi A
nimalia