Answer: They are heated up and turn into magma, then they are cooled and crystalize.
Explanation:
The biological term is a pedigree.
When you compare different organisms and see that they have the same or similar anatomic traits, it's reasonable to assume the organisms share a common ancestor where they would have gotten trait from. (evolution)
From the brightness of the light of course. If the brightness is increasing it means the the light source is approaching and if the brightness is decreasing it means the light source is leaving.
Hydrogen atoms and one oxegyn atom