Evolution of human colour vision other two human opsins. Middle Wavelength Sensitive Opsin (Green-sensitive opsin) – Encoded by the OPN1MW gene with a λmax of 530 found in the green region of the electromagnetic spectrum. Short Wavelength Sensitive Opsin (Blue opsin) – Encoded by the OPN1SW gene with a λmax of 430 found in the blue region of the electromagnetic spectrum. Certain parts of opsin genes and the vision of various species, including humans, has been known to change over time with different environmental changes. Recent studies have shown that primitive nocturnal mammalian ancestors had dichromatic vision consisting of UV–sensitive and red–sensitive traits. A change
Evolution of human colour vision place in Ancestral Boreoeutherian species with the 7 mutations on genetically reconstructed Boreoetherian short wavelength sensitive opsins. λmax values were shifted from a value of 357 to 411, an increase which indicated that human short wavelength sensitive opsins did indeed evolve from Ancestral Boreoeutherian species using these 7 mutations. Further analysis has shown that 4008 out of the 5040 possible trajectories were terminated prematurely due to nonfunctional pigments that were dehydrated. Mutagenesis results also reveal that ancestral human short wavelength sensitive opsin remained UV-sensitive until about 80 million years ago before gradually increasing its λmax by 20 75 million years