Species interactions lie at the heart of many theories of macroevolution, from adaptive radiation to the Red Queen. Although some theories describe the imprint that interactions will have over long timescales, we are still missing a comprehensive understanding of the effects of interactions on macroevolution. Current research shows strong evidence for the impact of interactions on macroevolutionary patterns of trait evolution and diversification, yet many macroevolutionary studies have only a tenuous relationship to ecological studies of interactions over shorter timescales. We review current research in this area, highlighting approaches that explicitly model species interactions and connect them to broad‐scale macroevolutionary patterns. We also suggest that progress has been made by taking an integrative interdisciplinary look at individual clades. We focus on African cichlids as a case study of how this approach can be fruitful. Overall, although the evidence for species interactions shaping macroevolution is strong, further work using integrative and model‐based approaches is needed to spur progress towards understanding the complex dynamics that structure communities over time and space.
Species interactions are pervasive in natural ecosystems. Species parasitize (Goater, Goater, & Esch, 2013) and eat one another (Pimm, 1982), cooperate (Stachowicz, 2001) and compete (Tilman, 1982), exploit one another for reproduction (Bronstein, Alarcón, & Geber, 2006), and alter both the physical (Jones, Lawton, & Shachak, 1997) and the selective environments (Futuyma, 2017; Matthews et al., 2014; Odling‐Smee, Erwin, Palkovacs, Feldman, & Laland, 2013) of other species. Our scientific understanding of species interactions underlies diverse fields of biology, and it continues to improve through models (Abrams & Cortez, 2015; Allhoff & Drossel, 2013; Week & Nuismer, 2019), observations (Meiners, Griswold, Harris, & Ernest, 2017; Ponisio, Gaiarsa, & Kremen, 2017) and experiments (Kloesener, Bose, & Schulte, 2017; Livne‐Luzon et al., 2017). For the purposes of this review, we define species interactions broadly: ecological associations between two or more different species in a common environment. This definition encompasses a wide range of phenomena that occur across dramatically different levels in the biological hierarchy, from individuals to populations, species and clades. Our discussions centre mainly on interactions that occur at the level of individual organisms. We also ignore hybridization, a type of species interaction with dramatically different consequences outside the scope of the current paper.