Certain signaling proteins, which are responsible for the development of innate immune function in almost all animals are also required for the formation of the dorsal-ventral (back-belly) axis in insect embryos. A new study by researchers from the University of Cologne's Institute of Zoology suggests that the relevance of these signaling proteins for insect axis formation has increased independently several times during evolution. For example, the research team found similar evolutionary patterns in the Mediterranean field cricket as in the fruit fly Drosophila, although the two insects are only very distantly related and previous observations suggested different evolutionary patterns. The new findings show that the evolution of axis formation in insects was actually much more complex than previously thought. The study has been published in eLife.