A Phylogenetic Analysis of the Caminalcules. I. The Data Base

-The Caminalcules are a group of "organisms" generated artificially according to principles believed to resemble those operating in real organisms. A reanalysis of an earlier data matrix of the Caminalcules revealed some inconsistencies and errors which necessitated recoding of some characters. The resulting differences with earlier results are minor. The images of all 77 Caminalcules are featured, those of the 48 fossil species for the first ime. The characters of the Caminalcules are defined and a data matrix is furnished for all Recent and fossil species. A new phenetic standard is proposed for the Caminalcules which divides them into five "genera." The true cladogram is revealed for the first time. Recent Caminalcules have evolved over 19 time periods. Five branches correspond to the phenetic genera but originate at greatly differing time periods. Four lines terminate in fossils. A series of measures for quantifying evolutionary change is defined, including measures for homoplasy, parallelism, and reversal. A survey is made of these measures and of other statistics of relevance to systematics for 19 data sets from the numerical taxonomic literature. The Caminalcules turn out to be compatible to data sets on real organisms with respect to all these measures, as well as with respect to evolutionary rates and species longevities. Thus, questions raised by an analysis of the Caminalcules should be of interest to systematists concerned with the analysis of data sets on real organisms. [Phenetic classifications; cladistic classifications; estimated cladograms; homoplasy; Wagner trees; Caminalcules; numerical taxonomy.] This paper, and others to follow, takes advantage of the opportunity afforded by a group of artificial organisms with a known phylogeny, the Caminalcules, to throw light on some of the questions concerning principles and procedures that currently engage the attention of taxonomists. There is considerable disagreement on the relative merits of phenetic and cladistic classifications (Sneath and Sokal, 1973; Eldredge and Cracraft, 1980; Wiley, 1981). Some workers contend that classifications based on phylogenetic principles are empirically better by various criteria of optimality (Farris, 1977, 1979a, b; Mickevich, 1978a, 1980; Schuh and Polhemus, 1980; Schuh and Farris, 1981). These claims have been questioned by others who find the evidence and methodology presented to be flawed (Colless, 1980; Rohlf and Sokal, 1980, 1981; Sokal and Rohlf, 1981a; Rohlf et al., 1983a, b). The empirical studies, and the arguments pro and con phylogenetic classifications derived in such investigations, suffer from a major impediment. All of the phylogenetic classifications reported in the literature are only estimates of the true phylogeny, which is unknown for all real organisms. By contrast he various results of this study merit serious attention because they can be examined against the benchmark of the true phylogeny of the group. The Caminalcules are artifacts created by the late Professor Joseph H. Camin of the University of Kansas and in effect represent a single simulation of the evolutionary process by rules that have not been made explicit. However, readers will find that these organisms, which have the advantage over other simulations in presenting a visual record to the investigator, illustrate a variety of evolutionary phenomena and are therefore of considerable pedagogical and heuristic value. The relevance of this data set to currently active issues in systematics will readily become evident to the reader of this series. I shall show that with respect to a substantial array of measurable properties, the Caminalcules are well within the range of empirically observed values for real taxonomic groups and that, conversely, for no property of consequence in numerical taxonomy are the Caminalcules beyond the range of observed values in real organisms. At the suggestion of the Editor and some