Butterflies and some mammals rely on color vision for survival. Francesca Frentiu, from the University of California, Irvine, and colleagues used epimicrospectrophotometry and gene sequencing to show that the photopigment opsin gene in the butterfly genus Limenitis has evolved similarly to the opsin gene in primates.1 The researchers measured light wavelengths reflected off the butterflies' tapetum lucidum and found a spectral range of 31 nanometers. They then partially cloned the gene for opsin and found that one polymorphism on Limenitis' gene for photopigments matches an opsin gene polymorphism in New World monkeys.
"There are few such instances of molecular convergence that have been described," writes Nicolas Galtier, a member of the Faculty of 1000 and a researcher at Montpellier University, in an e-mail. "This example suggests that perhaps there are not so many ways a species can evolve expanded color vision," he writes.
"What makes this work original and convincing ...
