After two decades of work, an international team of researchers has discovered how humans evolved to see all the colours of the rainbow. By figuring out how our ancestors swapped ultraviolet (UV) vision for blue-light (or violet) vision, they have finally pieced together a timeline for one of our species' most defining features.
"We have now traced all of the evolutionary pathways, going back 90 million years, that led to human colour vision," lead author and biologist, Shozo Yokoyama from Emory University in the US, said in a press release. "We've clarified these molecular pathways at the chemical level, the genetic level and the functional level." Read more.