Can you help with the following premises based on the change in the bone structure of the gasterosteus aculeatus species? Please read carefully the fragment below to answer the questions:

Lakes formed 12,000 years ago in Canada due to melting ice. The lakes were colonized by marine species of spiny fish called Gasterosteus aculeatus (three-spine stickleback). The current populations of these lake-dwelling fish show a reduction in their outer body armor when compared to their marine ancestors who have a broader armor. Outer body armor refers to the lateral bony plates that develop in these fish. Please see image below:

Research with these populations shows that the reduction in body armor benefits the rapid growth of these fish. This growth, in turn, translates into a decrease in mortality as predators tend to hunt small fish and an increase in nutritional reserve capacity during winter. These advantages allow the greatest reproductive success of these organisms.

Note: For additional information on what is argued in the previous excerpt, you can access the following link: https://www.nsf.gov/news/news_summ.jsp?cntn_id=112436

1. In your words. What is the case study about?
2. What role do mutations play in the fragment presented above?
3. How is the mechanism of natural selection represented in this situation?
4. How does a reduction in body armor represent an adaptation?
5. What is your personal opinion based on the case study?