Chapter 17: Classification

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Grouping bags that carry your books

1. Determine a common name for all the bags that
   carry your books
2. Divide your bags into 2 3 groups based on a
   common characteristic for each group
3. Divide each group from 2 into 2-3 groups
   depending on their common characteristics move
   them
4. Continue to do this 4 more times, getting more
   specific each time.
5. Once you get to an end point where you can no
   longer divide them up, start giving them two part
   names (Purpleus bistrapus)

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Taxonomy

• Determine a common name for all the bags that
  carry your books
• Divide your bags into 2 3 groups based on a
  common characteristic for each group
• Divide each group from 2 into 2-3 groups
  depending on their common characteristics move
  them
• Continue to do this 4 more times, getting more
  specific each time.
• Once you get to an end point where you can no
  longer divide them up, start giving them two part
  names (Purpleus bistrapus)

Kingdom
Phylum
Class
Order
Family
Genus species names
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Chapter 17 Classification
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What does it mean to classify?

• Could you imagine your closet or your drawers in
  your room not being organized?
• What if you just threw the kitchen utensils into
  a drawer?
• Puts order into a system or group
• Give some examples from your life where you have
  formed a classification system to make your life
  easier

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Taxonomy

• Field of biology that names and groups organisms
  according to their characteristics and
  evolutionary history

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Classification systems

• 1st system Aristotles grouped plants and
  animals by land, sea and air.
• Modern system - Carolus Linnaeus (1707 1778)

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Section 17.1 Objectives

• Relate biodiversity to classification
• Explain why naturalists replaced Arisotles
  system of classification
• What method did Linnaeus use to classify?
• List Linnaean levels of classification

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• Modern system is based on morphological
  similarities.
• Hierarchy of eight groups (Taxa)
• Domain New taxon. Eukarya
• Kingdom largest most inclusive grouping-
  Animalia
• Phylum (Division in plants)- Chordata
• Class - Mammalia
• Order - Primate
• Family - Hominidae
• Genus - Homo
• species most exclusive, specific group. Members
  of this grouping can mate and produce viable
  offspring - sapiens
• varieties same species but with slight
  differences
• subspecies same species, different location

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Some past systems
Linnaeus17352 kingdoms Haeckel18663 kingdoms Chatton19372 empires Copeland19564 kingdoms Whittaker19695 kingdoms Woese et al.197786 kingdoms Woese et al.199093 domains
(not treated) Protista Prokaryota Monera Monera Eubacteria Bacteria
(not treated) Protista Prokaryota Monera Monera Archaebacteria Archaea
(not treated) Protista Plantae Protista Protista Protista Eukarya
Vegetabilia Plantae Plantae Protista Fungi Fungi Eukarya
Vegetabilia Plantae Plantae Plantae Plantae Plantae Eukarya
Animalia Animalia Plantae Animalia Animalia Animalia Eukarya
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Whats in a name?

• Binomial nomenclature each species in given a
  two part name
• Genus name Homo or Homo
• species name species identifier usually
  descriptive - sapiens or sapiens
• Latin is the language of classification
  universal and does not evolve (Dead language)

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Section 17.2 Objectives

• What evidence do modern biologists use to
  classify organisms?
• What kind of information is presented in a
  phylogenetic diagram?
• How is a cladogram made?
• Explain how biomolecules can be used to classify
  organisms

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Today, we use Phylogeny (based on evolutionary
history) for classification

• Systematics organizes living things in the
  context of evolution
• Phylogenetic tree family tree that shows
  evolutionary relationships.
• Use morphology and embryological development.
• Look at early development.
• Zygote (1 cell) to morula(solid ball of cells),
  to blastula (hollow ball stage) with the
  blastopore (indentation of gastrula) becoming the
  anterior end of the digestive tract in most
  animals. In echinoderms (sea stars) and
  chordates (thats us), it is the posterior end.
  So we are more closely related to the echinoderms
  than the Arthropods (Insects and crustaceans)

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Blastopore
Zygote Morula Blastula
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Also used

• Fossil record
• Macromolecules comparison of DNA and proteins.
  More proteins in common, more recently two
  species shared a common ancestor.
• Molecular clock model compares amino acids in a
  protein sequence. Ie. Our Hemoglobin and a
  gorillas is only 1 amino acid off in a chain of
  146 amino acids.
• Chromosomes More similar the karyotypes, the
  more similar the organisms

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Cladistics

• Named for branches of trees called clades
• Uses certain features (derived characters) to
  show evolutionary relationships
• Derived characteristics unique feature to a
  group (feathers in birds)
• Cladistics, ignores when and where a branch
  occurs, using only derived characters to define
  each branch point by a fundamental character of
  evolutionary significance.

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• Cladogram is a useful way of organizing, in a
  visual way, the relationships between creatures
  that share and do not share derived characters.
• Construction begins with data a table of traits
  or characteristics that have evolved or been
  derived by the evolutionary process.

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Derived Characters Derived Characters Derived Characters Derived Characters Derived Characters Derived Characters Derived Characters
segmented jaws hair placenta multicellular limbs
kangaroo -
earthworm - - - -
amoeba - - - - - -
lizard - -
cat
sponge - - - - -
salmon - - -
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Amoeba Sponge Earthworm Salmon
Lizard Kangaroo Cat
Placenta
Hair
Limbs
Jaws
Segmented
Multicellular
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Monotreme mammals
Marsupial mammals
Placental mammals
Fish
Amphibians
Reptiles
Birds
Warm-blooded
Placenta
Early Internal development
Hair
Amniotic egg
Lungs
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Section 18.3 Objectives

• What evidence led to the development of the 3
  Domain system?
• What characteristics are used to differentiate
  between the domains?
• Describe the 6 Kingdom system and its
  characteristics
• What are some problems with the 6 Kingdom system?
• Explain why taxonomic systems are dynamic

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The New and Improved Six Kingdom System
Kingdom Cell Type of Cells Nutrition Representative organism
Archaebacteria Prokaryotic Unicellular Autotrophic or Heterotrophic Blue-green bacteria, Methanogens
Eubacteria Prokaryotic Unicellular Autotrophic or Heterotrophic E.coli, Staphylococcus, Streptococcus, Spirochetes
Protista Eukaryotic Uni, multi or colonial Autotrophic or Heterotrophic Amoeba, Paramecium, Euglena, Plasmodium, Diatoms
Fungi Eukaryotic Uni or Multicellular Heterotrophic Yeast, Mushrooms, Molds, smuts, rusts
Plantae Eukaryotic Multicellular Autotrophic (some heterotrophic) Mosses, ferns, Horsetails, Conifers, Flowering plants
Animalia Eukaryotic Multicellular Heterotrophic Sponges, Coral, Sea stars, EW, Insects, Fish, Amphibians, Reptiles, Birds, Mammals
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Archaebacteria

• Many live in harsh environments (extremophiles)
• Archae Ancient
• Asexually reproduces by binary fission

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Eubacteria

• Eu true
• Most of the bacteria belong here
• Asexually reproduces by binary fission

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Protista

• Pro first
• Plant-like, Animal-like and Fungus-like
  characteristics.
• Least clear cut of all kingdoms.
• Asexually by binary fission segmentation

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Fungi

• Absorptive heterotrophs.
• Cell walls made of chitin.
• Reproduces sexually and asexually

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Plantae

• Multicellular
• photosynthetic organisms
• a cell wall made of cellulose
• Reproduces asexually and sexually

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Animalia

• Multicellular
• ingestive heterotrophs.
• Reproduces asexually and sexually

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Three - Domain System

• Woese compared rRNA to show that living things
  can be grouped into 3 groups/domains
• The domains
• Bacteria (Eubacteria)
• Archaea (Archaebacteria)
• Eukarya (Everything else)

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Human Classification

• Domain - Eukarya
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primate
• Family Hominidae
• Genus Homo
• species sapiens

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Dichotomous key

• Uses a branching system of two features to
  separate steps. Helps in identification process
• 1A. With hair Mammal
• B. Without hair Go to 2
• 2A. Has scales Go to 3
• B. Does not have scales Go to 4
• 3A. Has a three chambered heart Reptiles
• B. Has a two chambered heart Fish
• 4A. Has feathers Birds
• B. Does not have feathers Amphibians

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Dichotomous Key

• Is a method for determining the identity of
  something by going through a series of choices
  that leads the user to the correct name of the
  organism.
• Dichotomous means "divided in two parts".
• At each step of the process of using the key, the
  user is given two choices each alternative leads
  to another question until the item is identified

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• 1a. Wings covered by an exoskeleton..... Go to
  2
• b. Wings not covered by an exoskeleton Go to
  3
• 2a. Body has a round shape.......Ladybug
• b. Body has an elongated shape.......Grasshopper
  
• 3a. Wings fold against body......................H
  ousefly
• b. Wings point out from sides...Dragonfly

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