Sea Snakes Regain Colour Vision: A Fascinating Evolutionary Discovery

Nine species of sea snakes from the Hydrophis genus have remarkably regained the genetic basis for advanced colour vision—a trait believed to be lost millions of years ago. This groundbreaking study, led by University of Adelaide PhD candidate Isaac Rossetto and Associate Professor Kate Sanders of the Environment Institute, challenges the idea that evolution only moves forward.

“These snakes show that evolution is dynamic,” says Isaac. “Adapting to new environments can mean reactivating traits once thought unnecessary.”

Descended from lizard-like ancestors with full colour vision, early snakes lost much of their visual capabilities when adapting to dim-light habitats. Today, however, Hydrophis species thrive in vibrant marine ecosystems, prompting a re-emergence of this complex trait.

Associate Professor Sanders highlights the significance: “This demonstrates how sensory functions can evolve anew to meet environmental demands.”

Further research is underway to explore whether these genetic changes enhance colour sensitivity, offering new insights into how lost traits can reappear in evolution. 

Image Credit: Olive sea snake, Indian Ocean Imagery - Getty