An SFI working group explores the ideas of contingency and determinism in various complex systems. (image: Robert Stump/Unsplash)

When the renowned paleontologist Stephen Jay Gould proposed that unpredictable events rather than a set of rules have determined the outcomes of evolution, he ruffled many feathers among evolutionary biologists. But in the decades since, they have realized that chance events, such as mutations and environmental changes, have influenced evolutionary outcomes. Complexity scientists have also pondered the role of so-called contingent events in complex adaptive systems beyond biology but the field has lacked structured discourse on the topic.

However, an SFI working group meeting July 22–24 hopes to change that. At “Contingency and Determinism in Complex Adaptive Systems,” researchers from various disciplines, including philosophy, physics, economics, archaeology, history, and biology, and complexity science will present their research and thoughts on the theme.

But what exactly is contingency — and why is it essential to consider determinism when talking about it? “The simplest definition of contingency is chance — that the origin of some biological future is purely due to chance rather than some cause,” says SFI External Professor Doug Erwin (Smithsonian National Museum of Natural History). On the other hand, proponents of determinism argue that specific evolutionary outcomes, such as photosynthesis in plants, would have occurred regardless of how evolution unfolded. “When we’re trying to identify generalities in any science, we often downplay the contingencies,” says Erwin. “But, I think there’s a tension between contingency and determinism in most systems we study at SFI.”

The first day of the meeting will focus on a broad discussion of the terms. Philosophers have interpreted contingency in myriad ways, says SFI Research Fellow Anthony Eagan, who is helming the meeting with Erwin and John Beatty, a professor in the Department of Philosophy at the University of British Columbia. Eagan is curious to know if the participants will agree on a general definition of the concept. 

The participants will present their unique perspectives on contingency in the context of their disciplines the next day. Eagan anticipates these talks will address some big mysteries: “How does contingency affect complex adaptive systems? Can we recognize contingency and determinism in these systems?”

The meeting may also shed light on whether scientists can incorporate contingency into models of complex adaptive systems across disciplines like economics and agriculture. “If we can, then presumably we’ll increase the predictive capacity of models — though that’s going to be super difficult given the unpredictable nature of contingency,” says Eagan.

The organizers don’t expect a specific outcome, such as a paper, from this meeting but are banking on the discussion to lead to a larger event in the future. 

Erwin is confident the meeting will help the participants broaden their thinking about contingency to other systems. Eagan, on the other hand, is eagerly anticipating the stimulating debates that might arise at the gathering. “I’ll be giving a talk on the opening day — and if someone can refute my claims or open my eyes to different ways of looking at things, it’ll be wonderful indeed,” he says.