A new study shows that sea snakes evolved 15 million years ago to adapt to changes in seawater, including the evolution of eyesight.
The research, led by the University of Plymouth in the UK and published in the journal Current Biology, provides evidence of where, when, and how often species adapt to color vision.
The findings suggest that snake vision has been genetically altered over millions of generations so that they can adapt to a diverse environment and still observe prey underwater .
The gene that produces the pigment in the snake eye has changed.
Their vision - especially the pigment-producing genes in their eyes - has changed so they can see prey and predators up to 75 meters underwater.
'In the natural world, it is clear that species must adapt as their surroundings change. But seeing the speed of vision changes for snakes in less than 15 million years is truly amazing, '' said Bruno Simoes, a lecturer in animal biology at the University of Plymouth.
Simoes argues that the speed of diversification of sea snakes relative to their land relatives has highlighted the severe challenges in their environment.
This study shows that the vision of snakes and mammals evolved very differently during the transition from land to sea. Sea snakes have retained or expanded their ability to see color compared to their terrestrial relatives, while webbing and marine mammals have experienced a decline in color vision. This contrast is more evidence of the impressive evolutionary diversity in snakes' vision.
In this study, the researchers also wrote that although inherited from highly visible lizards, the ability to see the color of snakes is limited (typically only seeing two tones) due to the faint living that their original ancestors passed on.
Olive snakes (Aipysurus laevis) breathe in the western sea of Australia.
Olive snakes (Aipysurus laevis) breathe in the western sea of Australia. Sea snakes can reach the ocean floor at a depth of more than 80 meters, but they will have to rise to the surface to breathe after a few hours.