Evolutionary Relationships among Rodents: Comments and Conclusions

Abstract

The Paris Symposium on Rodent Evolution brought together a variety of biologists (paleontologists, comparative anatomists, embryologists, molecular biologists, and geneticists) who shared a common interest in the assessment of phylogenetic relationships among rodents and other mammals. A diversity of methodological strategies for phylogenetic reconstruction was also represented, including traditional paleontological searches for anagenetic or ancestral-descendant relationships; cladistic analyses of dental and cranial features in fossil and extant rodents; phenetic and cladistic analyses of soft anatomical and developmental features; form-functional considerations of selected postcranial, dental, and soft anatomical traits; and maximum parsimony, cladistic, and immunological distance analyses of molecular data. Surprisingly, perhaps, this variety of methodologies and data was accepted with tolerance by most participants, and there was a genuine sense of willingness to listen and to learn on the part of the vast majority of participants. Semantic disagreements over the “best” approaches to phylogenetic analysis were kept to a minimum, perhaps because most participants were anxious to learn about any evidence that might shed light on the uncertainties surrounding the possible evolutionary relationships among the 50 families of extant and fossil rodents (as recognized by Carleton, 1984).