Phylogeny

• What is phylogenetic classification based on?

  Evolutionary relationships between organisms
• What does phylogenetic classification reveal?

  How closely related organisms are
• What are the advantages of phylogenetic classification?

  • Produces a continuous tree structure
  • Avoids forcing organisms into inappropriate groups
  • No overlap between the groups produced
• What do phylogenetic trees map?

  Evolutionary relationships between organisms
• What do the relative positions of branching points in a phylogenetic tree indicate?

  Distance of shared common ancestors
• What does the proximity of species in a phylogenetic tree indicate?

  Closeness of their evolutionary relationship
• Where is the oldest species shown in a phylogenetic tree?

  At the base (left) of the tree
• What does artificial classification rely on?

  Differences useful at the time
• What can misrepresent true evolutionary relationships?

  Similar physical features due to adaptation
• What evidence does modern taxonomy use to determine phylogeny?

  • Molecular comparisons (DNA, amino acids)
  • Development studies (embryonic similarities)
  • Anatomical examinations (physical characteristics)
  • Behavioural analyses (species behavior)
• What is the role of sequencing technology in phylogeny?

  Determines order of DNA, mRNA, and amino acids
• Why is cytochrome c often used in molecular analysis?

  It is essential for respiration in eukaryotes
• What does a more similar sequence indicate about species?

  They are more closely related
• What happens to species that have been separated for longer?

  They accumulate more mutations and changes
• What is the process of DNA analysis and comparison?

  1. Extract DNA from cells
  2. Process and analyze the DNA
  3. Obtain the base sequence
  4. Compare sequences to determine relationships