Unravelling eco-evolutionary dynamics: Understanding adaptation to global change

Ecology Letters emerged a quarter century ago through the collaborative efforts of the National Center for Scientific Research (CNRS) in France and Wiley, with the aim of establishing an international journal dedicated to the rapid publication of conceptually novel research in ecology. Respected by the scientific community, Ecology Letters has undoubtedly achieved remarkable success.

In celebration of its 25 years of existence, the Ecology Letters board of senior editors, the CNRS and Wiley introduce a series of special issues that will showcase state-of-the-art knowledge on various scientific frontiers in ecology. These issues will encompass both fundamental and focused investigations on diverse topics, including the very real challenges posed by ongoing global change. The first issue delves into the intricate boundary that lies between ecology and evolution. A subsequent issue, already underway, is slated for 2024 and will showcase the insights that long-term studies can bring to our understanding of how various ecological and evolutionary processes are influenced by environmental pressures.

Ecology, the study of interactions among populations and species at both local and landscape scales, and evolution, which explores how heritable characteristics undergo change over time within populations, have long been naturally intertwined, as is evident from their coexistence in academia, journal titles and professional societies. This intrinsic connection finds expression in the metaphor advanced by the Yale Professor G.E. Hutchinson in 1965, wherein the ‘ecological theatre’ serves as the hallowed stage for the enthralling ‘evolutionary play’. However, despite this inherent association, the fields of ecology and evolutionary biology have historically existed in relative conceptual isolation, rooted in the perception that evolutionary processes operate too gradually to exert substantial influence on contemporary ecological dynamics (Hutchinson, 1965). For example, it was not all that long ago that population dynamical theory on animal host–parasite interactions largely excluded genetics, and the question of whether genetic considerations even mattered was still considered an unknown (Read et al., 1995).

Nonetheless, the scientific landscape has undergone a transformative metamorphosis, catalysed by an increasing number of studies showcasing the simultaneous operation of ecological and evolutionary processes across diverse systems (Antonovics, 1976; Bassar et al., 2021; Hendry, 2017; Leibold & Chase, 2017; Pimentel, 1961). As the paradigm shifts, acknowledging the co-occurrence of these processes, the nascent field dedicated to studying their interaction is rapidly gaining attention, promoting a subdiscipline in its own right (Loreau, 2010).

At the heart of this paradigm shift lies the concept of eco-evolutionary processes (hereafter referred to as ‘eco-evo’), in which the focus is explicitly on research that aims to shed light on reciprocal interactions between ecological and evolutionary dynamics, and the role that these interactions play in driving population and community dynamics and processes of adaptation (Ferrière et al., 2004; Violle et al., 2012). Eco-evo outcomes are driven by the subtle influence of ecological processes, encompassing within and between species interactions and environmental fluctuations, on the trajectory of evolutionary change, subsequently reshaping the genetic frequency of underlying phenotypic traits (Matthews & Whittaker, 2014). These evolutionary alterations, in turn, influence ecological dynamics, reconfiguring species interactions with their environment, thereby engendering an ever-evolving cycle of intricate eco-evo feedback loops (Fussmann et al., 2007).

Indeed, while studies exploring eco-evo feedbacks extensively highlight the pervasive impact of ecology on evolution (‘eco to evo’), the reverse process clearly also occurs (‘evo to eco’). The comprehensive feedback loop remains relatively underexplored, and research is needed to elucidate these complex interactions, particularly with regard to increasing our ability to predict the outcomes for species and communities in natural ecosystems.

This special issue comprises of 11 articles, viewpoints, perspectives, letters and syntheses, collectively contributing diverse insights into the intricate relationship between ecology and evolution. Unravelling the reciprocal influences and feedback mechanisms that underpin the coexistence of ecological and evolutionary processes promises to furnish invaluable insights essential for conceiving and implementing innovative strategies to manage biodiversity and ecological systems increasingly subjected to anthropogenic pressures.