Ours is still the result of an evolutionary reclamation job and remains one pigment short of the tetrachromatic visual system found in birds and in many reptiles and fish.

• 我们的色觉依旧是演化改造工程的结果，比起鸟类与许多爬行类及鱼类的四色视觉系统，我们还是少了一个色素。