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THE USES OF TREES - Coggle Diagram

- - - - sibling species are much more likely to be more similar
- - - - many biogeographical facts make little sense assuming special creation but do make sense if
        
        a species has a definite site or region of origin
        
        a species achieves a broader distribution by migration (moving around)
        
        a species gives rise to descendant species in the various regions to which it migrates
      - Darwin emphasised dispersal
      - observation 1
        
        neither the similarity nor the dissimilarity of the inhabitants of various regions can be wholly accounted for by climate and other physical conditions
        
        similar climates and habitats occur in both the old world and the new world eg. deserts
        
        organisms inhabiting them are totally unrelated although they often look very similar
      - observation 2
        
        barriers of any kind or obstacles to free migration are related in a close and important manner to the differences between the productions [organisms] of the various regions
        
        highlighted the difference between marine species on the eastern and western coasts of SA
        
        marine species either side of isthmus of Panama are very similar as isthmus is only 3.5myo
        
        hypothesis is that isthmus was open in recent past
- - - - offer an insight into morphology of geographical past
      - allow us to increase phylogenetic and morphological knowledge
    - - can use fossils to time calibrate a tree
  - - - when removing a single fossil - ottoia - the tree is almost unresolvable
  - - - can fill in the gaps in the ghost ranges by looking at sibling lineages etc
      - gives us minimum implied gap
        
        size of gap that the lineage requires to make sense on the tree
- - - - T = K/2r
  - - - shorter generation time will accelerate the clock because it shortens the time to fix new mutations
    - - species-characteristic differences in polymerases or other biological properties that affect the fidelity of DNA replication, and hence the incidence of mutation
    - - changes in the function of a protein as evolutionary time proceeds
      - might particularly be expected in the case of gene duplication
    - - organisms are continually adapting to the physical and biotic environments, which change endlessly in patterns that are unpredictable and differently significant to different species