Systematic Botany - James Eckenwalder
January 17, 2013
Everything above the number in the phylogeny tree has a 1 and anything below has a 0. This is
an indication of relationship.
Phylogenetic and phenetic approach are post-WWII techniques
Phylogenetic school - only information on the tree that is considered important is the series of
branching events. And those are in essence speciations and times in the past. What they imply is
a relative recency of common ancestor. This depends only on cladistic information. All
groupings represented have to be monophyletic (group in which if you take any two members of
the same group and find their most common ancestor, look for the descendents of the common
ancestor and this is included in the group)
Phenetic approach uses only the distribution of character states and we use only characteristic
The evolutionary approach is traditional taxonomy. It uses all the information that is available.
This also takes into account the change that has occurred.
Synapomorohies imply monothetic groupings.
Polyphyletic - ex. Grouping Populus trichocarpa and Salix due to the hair characteristic.
Polythetic groups are ones in which the characters within the group are in essence scrambled and
mixed up. No singly character in a polythetic grouping is necessary or sufficient for grouping.
Not all of the taxa within a polythetic grouping can have any of the grouping characters; some
members will be lacking it. Each members have a preponderance of the characters and nothing
outside of the group do the characters predominate, they will exist scattered outside of the group
Monothetic groups in which a single character may be necessary or sufficient for group
membership. Ex. Characters 6 and 5 are clear synapomorphies.
APG3 - angiosperm phylogeny group is the most prominent traditional classifications. This will
be contrasted with Cronquist, which is one of the last traditional classifications.
Many APG groupings are very messy. There are also many parallelisms and reversals in
Organization of figure 1-2 is hierarchical. The nesting of groupings are hierarchical
organizations; there are groups within groups.