Evolving representations of biodiversity across curriculum reforms: a longitudinal analysis of science curricula (2013–2024)

This study examines how representations of biodiversity have evolved across science curriculum reforms in Türkiye implemented in 2013, 2018, and 2024 using a longitudinal document analysis. Biodiversity-related learning outcomes were coded according to their explicit or implicit representation, biodiversity dimensions, cognitive levels, and sustainability contexts. The analysis indicates a qualitative shift in how biodiversity is framed across curriculum versions, with increasing emphasis on conceptual depth and contextual integration. Biodiversity moves from a primary focus on identifying and classifying organisms towards a multidimensional and systems-oriented framework that incorporates ecosystem processes, genetic mechanisms, and human–environment interactions. Genetic diversity becomes more visible in later curricula through learning outcomes related to inheritance, mutation, adaptation, and biotechnology and is increasingly associated with higher-order cognitive processes. Challenges related to conceptual continuity across grade levels and reliance on implicit representations persist. The findings highlight the importance of structuring biodiversity education within a coherent spiral progression that explicitly connects genetic, species, and ecosystem dimensions through increasing cognitive demand and links to sustainability.