“More than half of all animal life exists in a parasitic relationship, and all life lives in symbiosis”

Our survival depends on species evolving to live together - but some relationships take dark turns

- By SOPHIE PAVELLE Illustration by NIC JONES

I'M IN EXETER CATHEDRAL AND I'M looking up at Antarctica.

This is Gaia by artist Luke Jerram: a 7m-diameter model of Earth suspended above the nave, created from detailed NASA satellite imagery of the planet's surface. The monumental installation is designed to summon 'the overview effect'. Commonly reported by astronauts, this describes a cognitive shift towards feelings of awe and a renewed urge to protect the planet.

Inspired by the Gaia hypothesis - the hivemind between chemist James Lovelock and biologist Lynn Margulis in the mid-1970s - Gaia reintroduces Earth as one self-regulating, interconnected system. These teachings reveal the planet's vitality and vulnerability, its strength and interconnection - a world teeming with relationships - driven by the environment and change.

As I orbited our planet that night, symbiosis was on my mind - the captivating situation where different species have evolved to live together to survive. Lynn Margulis championed symbiosis as the essential state of interbeing. Species join forces, share resources, operate within ancient evolutionary pacts of give and take - shaping ecosystems, binding pivotal connections and building resilience.

Perhaps you know symbiosis as synonymous with mutualism - a cosy narrative promoting equal shares in the relationship. But modern scientific understanding leads us towards an enigmatic version distinguished by raw inequality and reciprocal exploitation so precisely executed, it upholds ecosystem stability.

Symbiosis demands dark and dangerous lifestyles. Parasitism is its dominant form, where the suffering of one species enables the survival of another. More than half of all animal life exists in a parasitic relationship, and all life lives in symbiosis.