Phylogeny

• What system has been developed due to advances in genetics and microscopy?

  The three domains system
• What do the lengths of the lines in the three domains system refer to?

  Similarities based on genetics
• What are the main differences between Bacteria and Archaea?

  • Different cell membrane structure
  • Different internal flagellum structure
  • Different RNA polymerase
  • Archaea have proteins bound to genetic material
  • Different mechanisms for DNA replication and RNA synthesis
• What are the similarities between Archaea and Eukaryotes?

  • Similar RNA polymerase
  • Similar methods of DNA replication and RNA synthesis
  • Production of some proteins that bind to their DNA (like histones in eukaryotes)
• What does phylogeny refer to?

  The evolutionary relationships between organisms
• What do organisms share according to phylogeny?

  Common ancestors
• What do phylogenetic trees represent?

  • Hypotheses about evolutionary relationships among organisms
  • Built using morphological, biochemical, behavioral, or molecular features
  • Organize species into nested groups based on shared derived traits
• How are phylogenetic trees built?

  By comparing sequences of genes or proteins among species
• What does it indicate if closely related species have few sequence differences?

  They are more closely related
• What do nodes in phylogenetic trees represent?

  Common ancestors
• What can be inferred about individuals with a more recent common ancestor in a phylogenetic tree?

  They are more closely related to each other
• What are the advantages of using phylogenetic trees in classification?

  • Similar observable features may misclassify distantly related organisms
  • Organisms form a continuum rather than discrete groups
  • The Linnean system does not account for the length of time species have existed