Classification

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Classification

• As more was learned about cell structure in
  organisms, bacteria were removed from the protist
  kingdom and fungi were taken out of the plant
  kingdom.
• This lead to the five kingdom system, which was
  developed in 1969 by the
• American ecologist R. H. Whitaker. This system
  has served taxonomists well for over 30 years.

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Classification

• Whitakers Five-Kingdom system
• (1) Monera contains all the prokaryotes
  (bacteria).
• (2) Protista contains all the single-celled
  eukaryotic organisms and is further divided into
  three groups animallike protists, plantlike
  protists, and funguslike protists.

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Classification

• (3) Fungi contains the yeasts, molds, and
  mushrooms They have cell walls that contain
  chitin and are heterotrophic.The yeast are
  unicellular, but most other fungi consist of
  numerous long multicellular filaments.
• (4) Plantae (the plants) multicellular
  photoautotrophs with cellulose cell walls
• (5) Animalia (the animals) multicellular motile
  heterotrophs having cells that lack cell walls.

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Classification

• Six Kingdoms
• More recently the kingdom Monera has been divided
  into two kingdoms, making six kingdoms.
• Kingdom Archaebacteria includes organisms that
  live in extremely harsh environments, for
  example, extremely salty environments and
  extremely hot environments.

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Classification

• Kingdom Eubacteria it is the larger of the two
  prokaryotic kingdoms.
• It contains a wide range of organisms with many
  life styles. Some of the most important
  eubacteria are the cyanobacteria, also known as
  blue-green bacteria.
• These organisms are photosynthetic.

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Classification Six Kingdoms
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Classification A New System

• This new system institutes a taxon above the
  kingdom called the Domain.
• Under the new system, life consists of three
  Domains--Bacteria, Archaea, and Eukarya.
• The Bacteria and Archaea are all the
  prokaryotes--confined to a single kingdom under
  Whittaker's system. There are a number of
  distinctions between the two domains.

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Classification A New System

• These two domains are believed to have diverged
  very early in the evolution of life. Eukaryotes
  then diverged from Archaea, and they comprise the
  third domain, consisting of kingdoms of plants,
  animals, fungi,and several protist kingdoms.
• A great deal of scientific research continues to
  go toward discovering more about and supporting
  (or refuting) this system of classification.

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Classification A New System
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Phylogeny

• Phylogeny is the evolutionary history of an
  organism.
• It is the cornerstone of a branch of biology
  called systematic taxonomy.
• Systematics, as systematic taxonomy is commonly
  called, organizes the diversity of living things
  into the context of evolution
• A phylogenetic tree is a family tree that shows a
  hypothesis about the evolutionary relationships
  thought to exist among groups of organisms.

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Phylogeny
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Phylogenetic Tree Cytochrome c
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Phylogeny

• Phylogenetic trees are usually based on a
  combination of the following types of evidence
• (1) The fossil record
• (2) Morphology
• (3) Embryological patterns of development
• (4) Chromosomes and DNA