Crossroads, Milestones, amd Landmarks in Insect Development and Evolution: Implications for Systematics

Our understanding of insect development and evolution has increased greatly due to recent advances in the comparative developmental approach. Modem developmental biology techniques such as in situ hybridization and molecular analysis of developmentally important genes and gene families have greatly facilitated these advances. The role of the comparative developmental approach in insect systematics is explored in this paper and we suggest two important applications of the approach to insect systematics--character dissection and morphologicallandmarking. Exi~ng morphological characters can be dissected into their genetic and molecular components in some cases and this will lead to more and richer character information in systematic studies. Character landmarking will be essential to systematic studies for clarifying structures such as shapes or convergences, which are previously hard to analyze anatomical regions. Both approaches will aid greatly in expanding our understanding of homology in particular, and insect development in general.