Phylogenetic Trees

• anagenesis


  change within a lineage through time
• anagenesis does not generate diversity
• an example of anagenesis is the evolution of man
• cladogenesis


  lineage splits in two, divergent anagenetic evolution
• cladogenesis leads to increased diversity
• all of life is descended from a single ancestor
• all biological diversity results from cladogenesis
• phylogenetics


  science devoted to unravelling evolutionary relationships between organisms
• phylogenetic trees trace biogeographical history of organisms
• trees can identify conservation priorities of species or areas
• predict properties of understudied organisms and genes
• trees show relative regency of common ancestry
• monophyletic group


  clade, a group that includes all the descendants of a common ancestor and only the descendants
• paraphyletic group 


  group that includes some but not all of the descendants of a common ancestor
• founder of phylogenetics is Willi Henning
• character


  any features of an organism that form the basis of comparison
• characters can have more than one states
• characters include molecular, descriptive, and presence
• characters change from a primitive to deprived state
• traits from a plesiomorphic to a apomorphic state
• synapomorphies


  characcteristics from ancestral species shared exclusively by its evolutionary descendants
• synapomorphies does not mean monophyly