Structural diversity, functional plasticity: the role of de-generacy in Human Evolution.

This review article explores the concept of de-generacy as a fundamental yet underutilised principle in evolutionary anthropology. De-generacy, defined as structurally distinct elements performing overlapping functions, is widely recognised in genetics, neurobiology, and immunology but remains overlooked in cultural evolution. Distinguishing de-generacy from redundancy-where identical structures fulfill the same role-is crucial for understanding adaptability, resilience, and innovation in both biological and cultural systems. Despite its explanatory potential, de-generacy has been largely absent from anthropological discourse due to historical baggage and terminological confusion. The misuse of "degeneracy" in colonial and eugenic narratives has hindered its application, even as contemporary evolutionary theory-particularly the Extended Evolutionary Synthesis-highlights structural variation as a driver of adaptive complexity. Consequently, an opportunity to refine methodologies in anthropological research, particularly in modelling cultural transmission, has been overlooked. De-generacy is a distributed property of complex adaptive systems that, in many circles of science, has been hidden in plain sight, overlooked because of a reductionist bias, and ignored because the term itself is misleading. This article clarifies the distinction between de-generacy and redundancy and demonstrates its significance in biological anthropology. Empirical examples illustrate degeneracy across multiple domains, including linguistic variation, kinship terminologies, and ritual practices. A comparative case study of Indonesian Silek and Brazilian Capoeira provides a snapshot of how structurally distinct yet functionally similar cultural formations emerge across diverse contexts. These examples reinforce de-generacy as a key explanatory principle in cultural resilience and transformation. By integrating degeneracy into evolutionary anthropology, this article advances a more nuanced understanding of cultural transmission and transformation. Recognising structurally diverse yet functionally coherent practices enhances models of cultural evolution, moving beyond strictly adaptationist explanations. Ultimately, degeneracy provides a robust conceptual tool for analysing variation, complexity, and persistence in human evolutionary systems, warranting greater attention in interdisciplinary research.