Species And Taxonomy

• Define Phylogeny

  = Study of evolutionary history of groups of organisms.

  
  

  => tells which organisms are related to each other and how closely related they are.
• Define Taxonomy

  = Science of classification - involves naming organisms and organising them into groups.
• What are the 8 taxa? How are they arranged?

  Taxa = hierarchal levels of groups used to classify organisms.

  
  

  Domain

  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species

  
  

  = Arranged in a hierarchy, with the largest groups on top.

  
  

  = Organisms can only belong to one organism in the group at each level in the hierarchy - no overlap.
• Outline the taxa hierarchy

  Domain

  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• What is courtship behaviour?

  = Set of species-specific display behaviours in which an animal attempts to attract a mate of the same species and exhibit their desire to copulate.
• List the 3 ways in which advances in technologies/techniques can clarify evolutionary relationships.

  1. Genome sequencing.

  
  

  2. Comparing amino acid sequence.

  
  

  3. Immunological comparisons.

  
  

  4. Similarities in COURTSHIP BEHAVIOURS
• Outline how Genome Sequencing can clarify evolutionary relationships

  1. Entire base sequence of DNA can be determined (due to GS advances).

  
  

  2. DNA base sequence of one organism can be compared to DNA base sequence of another organism to see how closely related they are.

  
  

  => closely related species will have a higher % of similarity in their DNA base sequence.

  
  

  => can clarify evolutionary relationships - can compare DNA base sequences of one organism with others in same family (for example) ---> if significantly different then can be reclassified.
• Outline how Amino Acid Sequencing can clarify evolutionary relationships

  1. Proteins made of amino acids ---> sequence of amino acids in a protein is coded for by the DNA base sequence.

  
  

  2. Related organisms have similar DNA sequences and so similar amino acid sequences in their proteins.

  
  

  3. Cytochrome C, for example. The more similar the amino acid sequence of cytochrome C in two different species ---> more closely related species are likely to be.
• Outline how Immunological Comparisons can clarify evolutionary relationships

  - Antibodies of one species will respond to specific antigens on proteins, such as albumin, in the blood serum of another.

  
  

  1. Serum albumin from species A injected into B.

  
  

  2. Species B produces antibodies specific to all antigen sites on species A's albumin.

  
  

  3. Serum extracted from species B, containing antibodies specific to the antigens on the species A albumin.

  
  

  4. Serum from species B mixed with serum from species C blood.

  
  

  5. Antibodies respond to their corresponding antigens on albumin in series of species C.

  
  

  6. Number of similar antigens ---> more precipitate formed ---> more closely-related species.