Despite growing interactions between ecology and evolution, there still
remain opportunities to further integrate the two disciplines,
especially when considering multispecies systems. Here, we discuss two
such opportunities. First, we suggest to relax the focus on the
distinction between evolutionary and ecological processes. This focus is
particularly unhelpful in the study of microbial communities, where the
very notion of species is hard to define. Second, we propose that key
processes of evolutionary theory such as adaptation should be exported
to hierarchical levels higher than populations to make sense of
biodiversity dynamics. Together, we argue that broadening our
perspective of eco-evolutionary dynamics to be more inclusive of all
biodiversity, both phylogenetically and hierarchically, will open up
fertile new research directions and help us to address one the major
scientific challenges of our time, i.e. to understand and predict
changes in biodiversity in the face of rapid environmental change.