Back to the future with the evolutionary time machine

Luisa Orsini

Human-driven environmental change has been associated with loss of biodiversity and ecosystem services. Yet, we struggle to mitigate this loss and to regulate pollution. This is because the links between abiotic environmental change and biodiversity are dynamic and complex. Because of this complexity, it is challenging to convince regulators, politicians and the public of the causal correlation between our own activities and their consequences on biodiversity. Moreover, we know remarkably little about the mechanisms of resilience to future changes.

‘Space-for-time’ substitution and cross-generational studies in species with short generation time have provided important insights into evolutionary mechanisms of resilience. However, they have the main limitation of quantifying changes against an already shifted baseline and across a short time frame. A comprehensive understanding of past changes in biodiversity, and the causal correlations to environmental change can be achieved through the study of biological archives, which have the unique advantage of preserving temporal biological and environmental signals, allowing the reconstruction of multidecadal dynamics across space. The use of sedimentary archives enables time traveling into the past to pristine environmental conditions, providing a reference baseline to quantify changes in biodiversity caused by major shifts in abiotic environmental change. These long-term data are essential in predicting the future of biodiversity and ecosystem services because they enable us to account for species evolutionary response and for eco-evolutionary feedbacks. These mechanisms are currently ignored in model forecasts, which leads to overestimation of species survival under future global change scenarios.