The answer to this question would be: vitamin
Some bacteria can produce vitamin K2 in the intestine. Other bacteria also able to change vitamin K1 into vitamin K2. But the amount produced is not much, so human still need to fulfill it from the diet. Vitamin K has a role in calcium regulation and in blood clotting pathway.
Because they have different Cones. Which simply means that some animals see certain types of colors or even Infrared or Ultraviolet, in which Humans cannot see.
Rhenium is the very dangerous (hazard wise) it should be handled carefully and you should understand that THIS should not be taken lightly I hope this helps!:)
C; rolls in mud to cool off and deter flies All the other answers refer to structural (physical) adaptations.