Systematics

• Systematics


  Study of patterns of relationships among taxa through time
• Aspects of systematics


  • Taxonomy
  • Description
  • Identification
  • Nomenclature
  • Classification
  • Cladistics (Phylogeny)
• Cladistics


  Establishing relationships using shared derived characters
• Development of the classification system

  1. Carolus Linnaeus (1735) - 2 kingdoms

  2. Ernst Haeckel (1866) - 3 kingdoms

  3. Edouard Chatton (1925) - 2 empires

  4. Herbert Copeland (1938) - 4 kingdoms

  5. Robert Whittaker (1969) - 5 kingdoms

  6. Carl Woese et al. (1977) - 6 kingdoms

  7. Carl Woese et al. (1990) - 3 domains

  8. Thomas Cavalier-Smith (2000) - 7 kingdoms
• Taxonomical hierarchy


  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Scientific names


  More reliable, consist of genus and species
• Rules for scientific names

  • Written in italicized Latin/Latinized words
  • Priority of publication is considered
  • All taxa should have an author when first described
• Cladogram


  Shows how each organism is related by looking at shared derived characters
• Cladistics


  • Branches at every node can be rotated
  • Two lineages from the same node are sister taxa
  • No such thing as "most highly evolved species"
  • No extant or extinct group is considered ancestral to any other
• Outgroup


  Contains the same primitive characters as the ingroup but lacks the derived characters
• Sister taxa


  Two taxa branching off from a node
• Clade


  Groups of taxa
• Synapomorphy


  Shared derived characters
• Symplesiomorphy


  Shared primitive characters
• Autapomorphy


  Unique derived characters
• Monophyly


  Group of organisms belonging to the same taxon and sharing a common ancestor
• Paraphyly


  Group of organisms with a common ancestor but does not include all descendants
• Polyphyly


  Group of organisms which may not have a common ancestor and is only based on a common characteristic
• The two cladograms provided are equivalent
• Each level had a specific rank, such as kingdom, phylum, class, order, family, genus, and species.
• The classification system is based on the Linnaean hierarchy, which includes kingdom, phylum/division, class, order, family, genus, species.
• Classification systems are used to organize organisms into groups with similar characteristics.
• Systematic biology involves studying relationships between living things using morphological, physiological, ecological, genetic, and molecular data.
• Taxonomists use a system of classification that includes categories such as domain, kingdom, phylum, class, order, family, genus, and species.
• Taxonomical hierarchy

  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Taxonomical hierarchy

  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Taxonomical hierarchy

  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Scientific names consist of two parts - the first part is the genus name and the second part is the specific epithet.