Ch. 18 Classification Systems

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Ch. 18 Classification Systems

• Classification in biology, is the identification,
  naming, and grouping of organisms into a formal
  system.
• The vast numbers of living forms are named and
  arranged in an orderly manner so that biologists
  all over the world can be sure they know the
  exact organism that is being examined and
  discussed.
• Modern classification has its roots in the system
  of Carolus Linnaeus (Carl von Linné), who grouped
  species according to shared physical
  characteristics.

The father of modern taxonomy
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Taxonomy

• Hierarchy is a ranking system
• Taxonomy - The hierarchical system of naming,
  describing and classifying organisms using
  structural characteristics
• The groups to which organisms were assigned are
  called taxa (singular taxon)
• Linnaeus ranked the categories from the broadest
  and most general taxa (kingdoms) to the smallest
  the most specific taxa (individual species).

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Taxonomic Level of Order
King Philip Came Over For Green Spaghetti

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

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Binomial nomenclature(Naming System)

• Binomial nomenclature in its simplest form is a
  way of naming a species by means of two names
  both in Latin or Greek.
• The use of Latin or Greek names were used
  because these languages were understood by
  scientists everywhere
• The first name, which begins with a capital
  letter is known as the Genus it is always
  capitalized.
• The second part represents the Species is always
  printed with all letters in lower case.
• The scientific name must be either underlined or
  written in italics.

Grizzly Bear
Ursus arctos
Great White Shark
Carcharodon carcharias
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What Separates One Species from Another Species?

• Species-group of organisms that share similar
  characteristics and can breed with one another
  and their offspring can reproduce offspring.
• When organisms from different species breed with
  one another their offspring are sterile or
  infertile.

Male Donkey X Female Horse
Mule
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Male Horse X Female
Donkey (jenny)
Hinny
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Female Tiger X Male Lion
Female Liger
Male Liger
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Male Tiger X Female Lion
Tiglons or Tions
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Female Horse X Male Zebra
Female Donkey X Male Zebra
Zedonk / Zonkey
Zebroid / Zorse
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Bison X Domestic Cow
White Bass X Striped Bass

Beefalo or Cattalo
Hybrid Striped Bass
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Most taxonomist use a five-kingdom system. These
five-kingdom group organisms together that have
similarities in such fundamental characteristics
as major cellular structure, unicellular or
multicellular and methods of obtaining nutrients,
and now DNA evidence.
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Recent Advances

• The Three-Domain System
• Domain a more inclusive category than any other
  larger than a kingdom.
• Domain Bacteria includes the kingdom Eubacteria
  (true)
• Domain Archaea includes the kingdom
  Archaebacteria (ancient)
• Domain Eukarya includes the kingdoms Protista,
  Fungi, Plantae, and Animalia. P 459

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Evolutionary Classification

• Phylogeny the evolutionary relationships among
  organisms.
• Biologists now group organisms into categories
  that represent lines of evolutionary descent, or
  phylogeny, not just physical similarities.
• This strategy is called Evolutionary
  Classification.
• Cladistic analysis identifies and considers only
  those characteristics of organisms that are
  evolutionary innovations new characteristics
  that arise as lineages evolve over time, these
  are called Derived characters.
• Derived characters can be used to construct a
  cladogram, a diagram that shows the evolutionary
  relationships among a group of organisms.

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cladograms
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Dichotomous Key (Taxonomy Key)

• A tool that is used by scientists that work in
  the field when they come across a unfamiliar
  organism.

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Web Links

• http//www.nps.gov/cave/desertlb/reveg/rv_wq1.htm