1. calculation of similarity (or difference) and grouping species into sets is known as 'cluster analysis'
2. Adaptive Radiation & Convergent Evolution
3. 'Distance Matrix' is a matrix showing the number of characters in which each pair of species differ
4. Principle of Parsimony -the explanation that requires the least assumptions is best. Whether a character is a synapomorphy or a homoplasy, according to parsimony, is decided on how many evolutionary changes have to be assumed to fit an organism into one clade or another according to whether its shared character is a true synapomorphy or a homoplasy, e.g. frogs have loss of tails, like apes, but classing frogs with apes based on their shared character of loss of tails would require assuming more evolutionary changes than classing them with amphibians.
5. Evolution
6. Ecology
7. Diversity
   1. Taxonomy
      1. 'Clade' = a monophyletic grouping
      2. Morphology or phenetics do not lead to a taxonomy which is as useful in modern Biology as classification by cladistics or molecular sequencing
      3. Phenetic taxonomy is classifying organisms according to the number and degree of similarity of phenotypic characters
         1. What is a 'character' in phenetic taxonomy?
            1. choice of characters
            2. 'coding' of characters (convert into numbers, and 0=absence of n character, 1=presence of n character)
            3. calculation of similarity (or difference, i.e. classifying by number of diverging characters does not in itself mean cladistic taxonomy!)
            4. grouping of species into sets, based analysis of similarities
            5. converting these sets into genus, family, order, etc.
         2. Phenograms
            1. a Phenogram shows the degrees of difference and relatedness of phenotypic characters between species, by taking the numbers in a Distance Matrix as the lengths of lines in a tree diagram
            2. a phenogram must have a scale, but: the scale only shows the number of differences between pairs of species where they are supposed to divide and it cannot accurately show the number of differences between organisms in different taxonomic levels
      4. Cladistic taxonomy is classifying organisms according to shared and divergent derived characters
         1. Cladograms
            1. a cladogram does not have a scale
            2. each branch of a cladogram divides at a unique derived character
            3. organisms with the most shared derived characters are grouped together
            4. a Distance Matrix for building a cladogram starts with the most closely related Outgroup, which does not have any of the shared derived characters of the clade
      5. classifies characters as ancestral or derived
      6. a derived character shared by members of a clade is a Synapomorphy
      7. ancestral characters are called Plesiomorphies
      8. shared ancestral characters are called Symplesiomorphies, which are the opposite of synapomorphies
      9. a Homoplasy is a shared character that is not derived evolutionarily
      10. homoplasies can occur either by convergent evolution or by evolutionary reversal
      11. a Cladogram shows how organisms are related phylogenetically by shared derived characters e.g. birds and bats both have wings, but through convergent evolution not phylogenetic ancestry; apes do not have tails, but their absence of tails is a shared derived character
8. Life processes