Phylogenetic Relationships/Cladograms

• What indicates that organisms shared a common ancestor?

  Similar amino acid sequences
• How do shared derived traits relate to common ancestry?

  The more traits shared, the more recent the ancestor
• What can be used to construct phylogenetic trees?

  Traits gained or lost during evolution
• Why is molecular data more reliable than morphological traits?

  Molecular data provides more accurate evidence
• What do phylogenetic trees and cladograms represent?

  Hypotheses about evolutionary relationships

  
• How is a phylogenetic tree structured?

  It has nodes indicating points of divergence

  
• How does a phylogenetic tree differ from a cladogram?

  Phylogenetic trees indicate time; cladograms do not
• What is a clade?

  A group including all descendants of an ancestor
• What is the root in a cladogram?

  The initial ancestor common to all organisms
• What does morphology study?

  The form and structure of organisms
• What is a shared ancestral trait?

  A trait shared due to common ancestry
• What is a derived trait?

  A trait present in a lineage but absent in the ancestor
• How do derived traits indicate common ancestry?

  Shared derived traits suggest related lineages
• What is an outgroup in phylogenetics?

  A reference group for determining relationships
• What does the ingroup represent?

  The group of related species under study
• What does each node in a cladogram represent?

  A hypothetical common ancestor
• How can cladograms be manipulated?

  They can be rotated around each node
• What is a clade also known as?

  A monophyletic group
• What is the process for constructing a cladogram based on morphology?

  1. Construct a character table.
  2. Use "1" for traits present, "0" for absent.
  3. Identify the ancestral trait shared by all organisms.
• What indicates that a trait is ancestral in a character table?

  The trait possessed by all organisms