A mother who is blood type O can only pass an O allele to her son or daughter. A father who is blood type AB could pass either an A or a B allele to his son or daughter. This couple could have children of either blood type A (O from mother and A from father) or blood type B (O from mother and B from father).
At night, humans can use flashlights to spot animals that possess tapetum lucida by causing a phenomenon called eye shine.. Eye shine is the iridescent glow observed in animals when light is shone into their eyes, which floods the eye with light that is then reflected by the tapetum lucidum.
As one important example, human mothers and infants are heavily reliant on eye contact during their interactions. One study found that human infants look at the face and eyes of their caregiver twice as long on average compared with other apes. Clue to our humanity. Other ideas have also been proposed to explain why humans have such visible eyes. For example, white sclera might signal good health and therefore help signal to others our potential as a mate. Or, as one other recent study suggested, visible eyes might be important for promoting cooperative and altruistic behavior in individuals that benefit the group.