Jonas Salk a medical researcher and virologist, is famous for discovering and developing the first successful polio vaccine. He is also reknown for this thought provoking quote...

"If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish."
 

It really makes you ponder about the damage and compulsive greed that we humans are inflicting on the Earth.