Some evolutionary losses may not be lost forever
Biological Sciences researchers dive into sea snake genetics.
Nine species of sea snakes have now been identified as having regained the genetic requirements for advanced colour vision, demonstrating that once a complex trait has been lost to evolutionary time, it may be regained in some way.
Several sea snakes of the Hydrophis genus have regained the genetic requirements for advanced colour vision. Credit: Satish Parashar.
A University of Adelaide study, led by PhD candidate Isaac Rossetto, found the genetic trait may have existed in a common ancestor of the nine species, which all belong to the Hydrophis genus, dating back three million years.
Isaac previously identified one species of sea snake that had re-elaborated the visual function – the fully marine Hydrophis cyanocinctus, which did so in response to its spectrally complex environment.
With the re-elaboration now identified in so many species, Isaac says there is sufficient evidence to suggest evolutionary losses can be somewhat reversed.
“We often think of evolution as a force that moves in just one direction – forward. But really, an organism’s ecological circumstances are continuously dynamic, and sometimes becoming the ‘fittest’ means revisiting traits that were once less beneficial,” Isaac says.