Diversity and Destructive Oscillations: Camerano, Elton, and May

Abstract

In a greatly simplified sense, the universe can be conceived as an enormous dynamical system governed by feedbacks that span scales up to, and including, the cosmos. Within this whole-universe perspective, ecology forms an extremely dynamic subset, replete with feedbacks that start from some of the smallest scales (DNA) and extend all the way to the scale of the whole planet. This dynamic volatility, and its accompanying multi-scale feedbacks, makes for a fascinating area of study. While excellent work in ecology has compartmentalized subdisciplines with great success (e.g., population ecology), I want to briefly consider here an area of ecology that attempts to conceptually tackle the ground across ecological subdisciplines, and asks how multi-scale feedbacks govern the dynamics of whole ecological systems. It is the intrepid who tackle such complexity, and yet the very nature of ecology has pushed many scientists to attempt a glimpse into the inner workings of the machinery that comprises a whole set of interacting species within an environmental context (i.e., a food web or ecosystem). In this short piece, I will discuss some of the pioneers of this scientific frontier and the viewpoints that have challenged, and inspired, us to consider ecosystems from a unified perspective. Ecologists have long pondered the interconnectedness of life, and the dynamical implications of this web of interactions. In an early contribution unearthed by Joel Cohen (1994), Lorenzo Camerano (1880) envisioned the ecological network as a massive set of interactions that, when perturbed, yield decaying oscillations that spread through a food web in a manner akin to the way sound resonates through a pipe organ. The interaction of many singular sound frequencies (oscillations) merge into a coherent spectrum of sound, with some frequencies muted and others magnified. It is intriguing that this description from a young naturalist was phrased so abstractly. Here, Camerano (1880) was referring to the spectrum of sound frequencies as a metaphor for the spectrum of population dynamic frequencies that are associated with any given interaction (Fig. 1). Intriguingly, later theoretical development in both population and food web ecology would begin to think about decomposing whole system dynamics into their inherent species frequencies (oscillations), as well as attempt to discern the rules that govern the interactions of the many frequencies that underlie a network.