Without sunlight plants can undergo photsynthesis and cannot produce oxygen for humans to breathe and would cause the humankind to go extinct.
In this example of evolutionary development, we can see a selective advantage.
Developing of new characteristics, in this case, the spots on moth's wings is a part of the process of adaptation of organisms to their environment.
The new characteristics are acquired through mutations and natural selection filters the ones that are the most beneficial for the holder.
For example, a mutation which results in moths having shorter wings is disadvantageous, because it makes the individual who possesses it less likely to survive and reproduce.
On the other hand, developing of spots that resemble eyes can be advantageous, since it enables the holder of the trait to be more successful and more likely to leave offspring.
It's biproducts or by cutting it open and find out.
I believe that the youth movement originated with the baby boomers, the huge generation born after the world war II. By 1970, 58.2 % of the population in America was under the age of 35 years. The economic boom of the 1950s meant more families could afford to send their children to College. College life gave the young people a sense of freedom and independence. It was on college campuses across the nation that youth protest movements began and reached their peak.