Platinum: Mostly mined around that area.
Explanation:
What happens during daytime is, oxygen that gets trapped between filaments of algae, moves them to the surface and during night as O2 is not produced, they slowly sink to lower depths, and you don't see them
The finches adapted over time to better suit their environment that they were in -- the size and shape of their beaks changed as a result of natural selection.
Even though both parents still have blood type A, Dad can pass on either his A or his O gene version. Mom can also either pass on her A or her O. Because of this, you can see that there's 1 in 4 or 25% chance for a child to have OO, or blood type O.
