Chickens may illuminate how humans developed sharp daylight vision
(PHYSorg.com Biology)

Humans belong to a select club of species that enjoy crisp color vision in daylight, thanks to a small spot in the center of the retina at the back of the eye. Other club members include monkeys and apes, various fish and reptiles, and many birds, which must home in on their scurrying dinners from afar or peck at tiny seeds.