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Classification Powered By Docstoc
How does mail end up in your

    What is the purpose of an address?
   Your address serves as a way to classify you
    based on your location.

    Your address is unique to your house and
    differentiates your mailbox from all the other
    mailboxes in the world.

   Just as the mail system is set up in an orderly
    fashion that allows you to identify a specific
    mailbox, scientists have set up a classification
    system that allows you to uniquely identify each
    species on the planet.
   Classification is the grouping of objects or
    information based on similarities.
   When you classify objects, you separate a large
    group of objects into smaller and smaller sub-
    groups based on similar characteristics until
    each object is identifiable by its unique
   With over 2 million species on Earth, scientists
    needed to design a system if classification in
    order to differentiate one species from another.
   The branch of biology that deals with grouping
    and naming organisms is called taxonomy.
                 The History of
   The first method of classification
    was developed around 350 B.C
    by the Greek philosopher
   Aristotle’s classification system
    grouped plants according to their
    size and structure, and grouped
    animals according to where they
    lived (land, air, or water).
   However, Aristotle’s system failed
    to show natural relationships
    between organisms.
   In the late 18th century, a Swedish
    botanist named Carolus Linnaeus
    developed a classification system
    that is wisely used today.
   Linnaeus analyzed physical
    characteristics of organisms and
    classified them based on close
   Linnaeus designed a classification
    system called binomial
    nomenclature which classifies each
    organism using two Latin names.
       Binomial Nomenclature
   According to Linnaeus’ system of binomial
    nomenclature, each organism is assigned two
   He first name identifies the genus of the
   A genus is a group of closely related species.
   The second name identifies the species or
   The species name usually describes the
   Example: Canis familiaris = Dog
               (genus) (species)
   The two word name assigned to each species
    through binomial nomenclature is called a scientific
   -> Scientific Name: Belis perennis
   However, people usually refer to organisms using
    the organism’s common name.
   -> Common name: Daisy
   Common names do not tell how organisms are
    related or classified, and they can also be
   It is important that scientific names do not change,
    so they are assigned in Latin, a language that is no
    longer spoken (and therefore does not change).
   Scientific names are either italicized or underlined,
    and the first letter of the genus is capitalized, while
    the first letter of the species is not.
        Taxonomic Categories
   In taxonomy, organisms are grouped in a series
    of categories called taxa (singular = taxon)
   When classifying an organism, biologists place
    the organism in a broad group known as a
   The organism is then placed in a series of sub-
    groups (taxa) that becomes increasingly specific
    until it is uniquely identifiable.
           Progression of Taxa

                                 Bobcat              Lynx
   Kingdom (most broad)         Animalia      Animalia
   Phylum                       Chordata      Chordata
   Class                        Mammalia      Mammalia
   Order                        Carnivora     Carnivora

   Family                         Felidae   Felidae
   Genus                          Lynx      Lynx
   Species (most specific) Lynx rufus Lynx canadensis

   (“King Phillip Came Over For Good Soup”)

        Determining Relationships
   There are four main ways
    to determine relationships
    between organisms:
   1. Evolutionary history:
       Taxonomic compare
        structure of modern-day life
        forms with those found in
        fossils to determine
        evolutionary histories.
          The evolutionary history of
           a species is called
            Evolution: Change: All in the
        Evolutionary Relationships
   2. Development
       Similarities in the
        development stages of
        animals help determine
        relationships, and can
        help determine if two
        animals have a
        common origin.
    Evolutionary Relationships
   3. Biochemical relationships:
       Closely related species have
        similar DNA sequences, and
        therefore, similar proteins.
       The more amino acid
        sequences two species have in
        common, the more closely
        related they are to each other.
            Example: Human and
    Evolutionary Relationships
   4. Behavior:
       Even though two species may look similar,
        distinct differences in their behavior may
        identify them as different species.
            Example: Mating calls of frogs
        Domains and Kingdoms
   There are three domains
       Bacteria
       Archaea
       Eukaryota
   There are six kingdoms
       Eubacteria
       Archaea
       Protista
       Fungi
       Plantae
       Animalia
Three Domains