Giobbe Forni

I. INTRODUCTION Evolutionary change does not always take the appearance of a modification of pre-existing features. Sometimes a change can emerge in the form of a disruptive novelty, something that has puzzled evolutionary biologists since the birth of the discipline (Wagner & Lynch, 2010). Still, evolution can exhibit a different, but equally striking pattern of change: the reinstatement of a lost trait, or trait reversal.

Abstract A new species of dwarf mantis, Ameles serpentiscauda sp. nov. endemic to Sardinia (Italy) is described. This taxon displays a highly elaborate courtship behavior, characterized by coordinated movements of the abdomen, cerci and terminalia, which is reported here for the first time, and compared with known behavioral traits in the genus Ameles. An integrative framework has been used, combining these ethological data with detailed morphology and molecular phylogenetics.

Abstract After the loss of a trait, theory predicts that the molecular machinery underlying its phenotypic expression should decay. Yet, empirical evidence is contrasting. Here, we test the hypotheses that (1) the molecular ground plan of a lost trait could persist due to pleiotropic effects on other traits and (2) that gene co-expression network architecture could constrain individual gene expression.