ABSTRACT
Arthropoda is by far the most numerous and most speciose phylum of the animal kingdom. From antiquity, arthropods have attracted the interest of naturalists. During the last century, an arthropod, the fl y Drosophila melanogaster has been the model animal in many fi elds of biology, and can be viewed as the ‘source’ of modern genetics (Morgan 1928) and developmental genetics (Lewis 1978; Nüsslein-Volhard and Wieschaus 1980). Still, at the dawn of the 21st century, many questions remain unsolved about the phylogeny of arthropods, which most often are related to development.
