M1:t6: Phylogeny

• phylogeny


  evolutionary history of life on earth

  • relationships are inferred from nucleotide seqs
  • groups are organised according to molecular similarity and measures of diversity of life ‘
• genetic diversity 


  measure of the diversity of life on earth

  1. gene mutation
  2. selective pressure
  3. gene transfer
• 4 revolutions

  1. lineages and haeckel
  2. chatton: pro and euk
  3. whittaker: 5 kingdoms
  4. whose: 3 domain system
• measures phylogeny

  • comparing gene seqs <— small subunit rRNA 16s and 18s
• why RNA

  • universally distributed
  • functionally homo
  • highly convyed
  • able to tell diff b/w organisms
• phylogenetic tree


  closer related = later branches
• consevred vs variable regions

  conserved: not much change

  variable: lots of change
• what are viruses

  • not alive and no ribo
  • cannot replicate outside host cell