The best evidence of such phenomena could be a population's genetic variation decrease.
When a population bottleneck occur it means that for some reason (i.e. environmental events) the size of a population is largely reduced. This leads to reduction of the genetic variation in that new smaller population. When a bottleneck occur, the founder effect is normally seen, which is that one population is established by a small group of a previously larger population leading once again the genetic variation, now though with a bigger population, to be very reduced.
        
             
        
        
        
Answer:
Box one: A compound
Box two: bonded chemically
Explanation:
it's a molecule, which is a collection of atoms bonded together chemically through their electrons.
hope that helps!