Not just creatures: fungi, plants, and bacteria all have it. Also Cave fish that haven't been isolated as long (more then 3 million years) still have it. So i

Not just creatures: fungi, plants, and bacteria all have it. Also Cave fish that haven't been isolated as long (more then 3 million years) still have it. So it's really really weird that placental mammals (which includes all non egg laying or marsupial mammals, including us) don't have it. It lends additional support to the Nocturnal Bottleneck theory https://en.wikipedia.org/wiki/Nocturnal_bottleneck https://en.wikipedia.org/wiki/Nocturnal_bottleneck