The hidden twists of biodiversity: lessons from Earth's geological past

Biodiversity is most often discussed in negative terms, with human activity accelerating species extinction. However, Earth's geological history shows that such processes are not new, argue two Tartu University academics.

Biodiversity — the remarkable variety of life on Earth — has dominated scientific and public discourse in recent years, almost exclusively through a lens of loss. Human activity, from deforestation to urbanisation and climate change, is widely acknowledged to be accelerating the extinction of species at an alarming rate. Yet the geological record of our planet tells a far more nuanced story.

What History Teaches Us

Martin Zobel, academician and professor emeritus of plant ecology at the University of Tartu, and Maarja Öpik, academician and professor of molecular ecology, also at the University of Tartu, argue that today's biodiversity crisis, while serious, must be understood within the broader sweep of Earth's deep history. Mass extinction events and dramatic shifts in species composition have occurred repeatedly over hundreds of millions of years — long before humans walked the Earth.

The authors point out that life has proven extraordinarily resilient. Each major extinction event in the fossil record was followed, eventually, by a recovery — often producing entirely new forms of biological diversity. This does not diminish the urgency of current conservation efforts, but it does invite a more sophisticated understanding of what biodiversity is, how it changes, and what forces drive those changes.

The Complexity of Ecological Dynamics

Zobel and Öpik emphasise that biodiversity is not simply a count of species present in a given area. It encompasses complex interactions between organisms, their environments, and even the invisible world of soil fungi and microbial networks. These hidden connections frequently determine which plants and animals can survive in a given ecosystem — and which cannot.

The piece serves as a reminder that ecological science, at its best, resists simple narratives. While human-driven extinction is a genuine and present danger, understanding the full picture of how life diversifies, persists, and recovers requires engaging with the deep, often invisible complexities that have shaped our living world across geological time.