stystematics modern chuchu

• Classification is the grouping of things accdoring to characteristics.
• Taxonomy is the science of classifying organisms.
• Taxonomy are composed of four components namely: Description, Identification, Nomenclature, Classification.
• Systematics covers three (3) fields which are:

  1. Taxonomy (DINC)
  2. Evolution - happens when there is Reproductive Isolation. There are modifications and changes.
  3. Phylogenetics
• Some early classification systems

  • Aristotle grouped animals according to the way they moved. He also grouped animals based on their color (Green - Plants, Not Green - Animals)
  • John Ray - Earliest taxonomist who first used the term "species"
• Binomial Nomenclature was developed by Carl Von Linne or Carolus Linnaeus.
• Binomial Nomenclature is a two-name system.
• Binomial Nomenclature is the use of Latin words.
• Binomial Nomenclature = Scientific names. These are italicized or underlined separately:

  • Genus is capitalized (first letter)
  • The rest is lower-cased
• Scientific names are important to give a universal and stardized way to refer to organisms. Common or vernacular names vary worldwide while Scientific names don't.
• Eight classification groups of Living things

  • Domain
  • Kingdom
  • Phylum or Division
  • Class
  • Order
  • Family
  • Genus
  • Species
• Phenetics focuses on the overall similarity among organisms based on observable traits.
• Cladistics or Phylogenetics focuses based on common ancestry. They focus more on their genetics or molecular traits.
• Phenetic classification - those organisms most similar to one another are classified more closely together.
• Problems with phenetic classification is that it can be arbitary (random choices). What is big to me can be small to others.
• Phylogenetic Classification

  • based on known evolutionary history.
  • reflects pattern of evolution
  • not ambiguous
• Why Phylogeny matters (OCE)

  • Organize biodiversity
  • Correct classification and identification
  • Evolutionary inference
• Phylogenies are fundamental tool for organizing our knowledge of the biological diversity we observe in our planet.
• Phylogenetic trees are branching diagram depicting relationships among various species based on their morphological or molecular characteristics.
• How do we interpret and understand

  phylogenies?

  Through phylogenetic trees
• Types of phylogenetic trees

  1. Circular
  2. Triangular
  3. Horizontal
• Lineages refers to relationships through time between ancestors and descendants.
• Clade is a grouping that includes:

  1. All common ancestors
  2. All descendants
• Clade in a Phylogenetic Tree is also known as the Monophyletic Group.
• Apomorphy refers to derived (new) feature.

  
• Apomorphies are result of evolution. Taxa sharing apomorphies are grouped togeteher because it underwent same evolutionary history.
• Why study Systematics? (FIPCOF)

  • Foundation of Biology
  • Integrative, unifying science
  • Practical value - economically important ants
  • Conservation Biology -determine rare and endemic
  • Origin and evolutionary relationships
  • FUN
• Phylogenetic Systematics is the reconstruction and study of evolutionary relationships.
• Evolutionary theory - the similarity among species is due to a common descent or inheritance from a common ancestor.
• Phylogeny - historical relationships among lineages or organisms such as their genes.
• Willi Hennig

  • German Entomologist (focus is insects)
  • proposed that systematics should reflect the known evolutionary history of lineages as closely as possible. This approach he called, "Phylogenetic Systematics"
• Phylogenetics = Cladistics


  Followers of Hennig are called "cladists" because of the emphasis on recognizing only monophyletic groups.
• Phenetic


  overall similarity
• Cladistics


  shared derived characters
• Pre-existing feature in species


  Plesiomorphic

  Primitive

  Ancestral
• New feature


  Apomorphic

  Derived

  Advanced
• Autapomorphy


  Uniquely derived charateristics
• Synapomorphy


  Shared derived trait(s) by two or more taxa
• Sister Taxa


  each of two descendant lineages from one common ancestor
• Monophyletic Group


  includes most recent common ancestor of the group and all of its descendants.