Our planet is facing rapid environmental change, and understanding how different animals adapt at a genetic level is a critical challenge. However, most omics research relies on having a complete genetic map, or "reference genome," which is only available for a small fraction of all species. This major limitation prevents us from studying the vast majority of Earth's biodiversity. The REFLECT project will solve this problem by developing a new, groundbreaking computer program (a bioinformatics pipeline) that works without needing a reference genome. This pipeline will analyse the gene activity (transcriptomics) of various animals, from marine invertebrates to hibernating mammals, to discover how their genes turn on and off in response to environmental stressors like ocean acidification or extreme temperatures. The project will produce an easy-to-use, open-source tool that will be made freely available to researchers worldwide. This will democratise advanced molecular research, enabling scientists to uncover the secrets of adaptation in any species, regardless of its genomic resources. The project's findings will generate vital knowledge for biodiversity conservation and contribute to our understanding of how life survives and thrives under extreme conditions.