ABSTRACT
This chapter focuses on phyletic seriation and then on frequency seriation. It illustrates how these two forms of seriation differ in terms of the scale of the units typically used in each, and how graphs displaying each influence whether one see cladogenetic, anagenetic, or reticulate evolutionary modes. Phyletic seriation focuses on changes in character states that make up the definitions of artifact classes. Frequency seriation, as typically implemented in a centered-bar graph, obscures evolutionary mode in favor of sequence. Dean's diagram not only epitomizes how important classification is to phy-logenetic research but also highlights differences in the kinds of trees that can be used to illustrate phylogenetic relations. One critical difference between seriation and cladistics is that the latter assumes that the evolutionary mode is always cladogenetic. Another difference is that in cladistics the temporal sequence of various taxa in different clades may be obscured.
