Page:The Gall Wasp Genus Cynips.pdf/67

 PHYLOGENETIC HISTORY

of the phylogenetic history of any group of organisms and biologic interpretations of taxonomic data depend for their validity upon the soundness of the available classifications of the group. If the catalogs are poorly made,one may draw no conclusions or, what is worse, draw conclusions as fantastic as the hobgoblins of primitive imagination. But if the taxonomic arrangement brings together species of common ancestry and accurately portrays the varying degrees of relationship between those species, a classification becomes one of the most powerful tools available for the evolutionary interpretation of biologic phenomena. It becomes a code by which one may translate the biologic and distributional data into the story of the origin and paths of dispersion and the order of development of each species and of each biologic characteristic of a group, from its primitive beginnings and thru the several stages by which it evolved the peculiar phenomena which we find today.

Phylogenetic interpretations of the genus Cynips have heretofore been impossible because cynipid genera, in common with the genera of many other insects, have been established for the most part upon “diagnostic” characters of insect morphology. These have been drawn from the toothed tarsal claw, the dorsally produced and naked abdomen, and the hairy thorax of the agamic form of the species folii, the genotype of the group (see Mayr 1870-1905, Dalla Torre and Kieffer 1910, Beutenmüller 1911, and Weld 1922-26, where the names Dryophanta or Diplolepis are used instead of Cynips). The insects included in the genus thus defined differed in many points of structure which, however, were consistently ignored. The genus included both black oak and white oak species, species that live in galls on flowers, leaves, stems, and roots, and galls of every conceivable type of structure (e.g., see plates 12 to 17 in Beutenmüller 1911). There were species with divergent types of life histories. There were species that we shall ultimately have to assign to 8 or 10 distinct and largely unrelated genera. The extent to which our own interpretation differs from previous treatments becomes evident in the following table. (61)