Phylogenetic Inference and Methodology as Applied to the Vertebrate Record

Abstract

The determination of relationships among living organisms is still one of the fundamental issues in comparative biology. The history of lineages is generally thought to be the province of paleontology, although phylogenetic reconstruction can be done with extant organisms alone. The major contribution of paleontology is that it places the history of lineages on the geological time scale and gives an idea of changes in diversity through time, but it does not necessarily provide us with the evidence of phylogenetic relationships or give the definite answer in the search for ancestors (Schaeffer, et al., 1972). Furthermore, the problem of phylogenetic inference is separate from that of classification because there can be only one set of correct phyletic relationships, but there may be several classificatory systems depending on one’s belief concerning the function of classification. However, there are many systematists who desire a classification that will faithfully depict phylogenetic pathways. Nevertheless, it is difficult to obtain a close correlation between classification and phylogenetic data that will satisfy all students of a particular group, but in order to make such an attempt the basic operational criteria must be re-examined frequently.