Plasticity-led evolution of gut length in wild medaka

A study published in the Proceedings of the National Academy of Sciences (PNAS), Volume 123, Issue 18, in May 2026, investigates the phenomenon of plasticity-led evolution concerning gut length in wild medaka fish. The research highlights how phenotypic plasticity, specifically changes in gut morphology in response to environmental or dietary factors, can drive evolutionary processes in natural populations. By examining wild medaka, the study provides empirical evidence supporting the theory that adaptive plasticity can precede and facilitate genetic assimilation, leading to permanent evolutionary changes. This finding contributes significantly to the understanding of evolutionary biology, particularly in how organisms adapt to changing environments through flexible physiological traits before genetic fixation occurs. The publication in a prestigious journal like PNAS underscores the scientific importance of these insights into the mechanisms of evolution and adaptation in vertebrates.