Underwater adaptation: Blue-shifts in whale vision

What is it about?

Rhodopsin is the visual pigment protein in the rod cells of your eyes that reacts to light, and is particularly important for vision in dim/dark environments. In whales, rhodopsin is more sensitive in the blue part of the light spectrum to maximize visual sensitivity in predominantly blue underwater light. Here, not only do we show that this blue-shift in sensitivity is the result of specific changes to the rhodopsin gene sequence, but that these changes have evolutionary signatures of positive natural selection.

Featured Image

Why is it important?

By demonstrating that positively selected genetic changes are directly associated with spectral functions, our work makes a compelling case that the blue-shifts in whale rhodopsin are, in fact, adaptive. Because whales have terrestrial ancestors, they are extraordinary models of macroevolution, but we still know very little about how these major transitions happen at the genetic level. Ours is one of few studies to make the leap between DNA and organism, adding a piece to the large puzzle that is whale evolution.

Perspectives