Compare and contrast cladistics and phylogeny. what are their advantages and disadvantages? which is the most useful in understanding how an organism developed into its current form? which concept most strongly supports your opinion about the origin of any given organism?

Cladistics is concerned with entire branchings by grouping all the common  descendants into a clade as a related group and no others.this is a narrower definition of an older, less precise concept.  cladistics is a way of grouping the related branches based on sharing derived characters within the group. however these characters are not found in other species except by convergence.
phylogeny is a way of tracking evolutionary relationships based on shared characters  based on artificially defined levels of taxonomy. this method allows convergent characters to be grouped despite their having followed a separate evolutionary path. taxonomy is the rank levels while phylogeny is the path through the ranks. 
i hope this .