Implications of shallow tethys and the origin of modern oceans

Cladograrns resemble directed Prim networks or Wagner trees, and are usually programmed by parsimony, i.e. the program searches for the least number of steps to achieve a cladistic synthesis. Large matrices can yield an almost infinite number of possible trees; and even when differences of only a few steps are involved there are numerous plausible solutions. Parsimony and other factors, such as Nelson and Platnick's assumptions, act as Occam's razor, reducing these to a manageable few.