Abstract
Digital twins (DT) are simulation models that so closely replicate reality in their behaviour that experts may believe model output to be real. Plankton offer worthy yet tractable biological targets for digital twinning, due to their relatively simply physiology and significant role in ecology from theoretical studies through to planetary scale biogeochemistry. Construction of dynamic plankton DT (PDT), representing a supreme test of our understanding of plankton ecophysiology, would form the basis of education and training aids, provide platforms for hypothesis setting/testing, experiment design and interpretation, and support the construction and testing of large-scale ecosystem models and allied management tools. PDTs may be constructed using concepts from systems biology, with system dynamics, including feedback controls akin to biological (de)repression processes, to provide a robust approach to model plankton, with flexible core features enabling ready and meaningful configuration of phenotypic traits. Expert witness validation through Turing Tests would provide confidence in the end product. Through deployment of PDTs with appropriate input controls and output (visualization) tools, empiricists are more likely to engage with modelling, enhancing future science and increasing confidence in predictive operational and also in long-term climate simulations.