Katja R. Kasimatis

1 Introduction A central challenge to explaining and predicting biodiversity in multispecies communities is to disentangle the contributions of distinct modes of interaction that influence species coexistence and exclusion (Chesson 2000; Götzenberger et al. 2012; Levine et al. 2017).

Abstract Diverse small RNA pathways, comprised of Argonaute effector proteins and their bound small RNA molecules, define critical systems for regulating gene expression in all domains of life. Some small RNA pathways have undergone significant evolutionary change in nematode roundworms, including gains of novel Argonaute genes and losses of entire pathways.

Abstract Sex-specific regulation of gene expression is the most plausible way for generating sexually differentiated phenotypes from an essentially shared genome. However, since genetic material is shared, sex-specific selection in one sex can have an indirect response in the other sex. From a gene expression perspective, this tethered response can move one sex away from their wildtype expression state and impact potentially many gene regulatory networks.