Toward Phylomics in Entomology: Current Systematic and Evolutionary Morphology

Abstract

Morphology, encompassing the study of phenotypic form and function, is one of the ancient branches of human knowledge and is foundational for organismal classification. Two decades into the current century, the specialized biological knowledge of the history and pattern of evolution has been revolutionized by genome-scale sequencing technologies, and cryptic variation within and among species is quantifiable even with a few genetic markers. The application of statistical phylogenetic models of nucleotide and amino acid substitution to sequence data has enabled revised interpretations of morphological identities-be they population-level generalizations, such as species diagnoses, or the definition and homology of specific anatomical entities-and evolutionary transformation across the tree of life (e.g., insect genitalia, ancestral morphology of Polyneoptera). These models are also being adapted for phylogenetic analysis of morphological data, allowing explicit incorporation of fossil terminals and their stratigraphic information. In this special collection of research in Insect Systematics & Diversity (ISD), we present six papers on the topic of Current Techniques in Morphology. These papers span an arc from integrated methods of phenotype observation and visualization to methods and background for phylogenetic modeling of morphological characters. In this editorial, I review the central role of anatomical classification and anatomical terminology in systematic by way of outlining the special collection. I argue ultimately for a reconceptualization of phylogenetic morphology.