I’m guessing it is a peaceful, harmonious atmosphere in the ecosystem, until humans come along and start to disrupt the flow and peace around them.
Hope this helps!
The answer is 1. In this sentence, the speaker describe a statement believed by many people, with which the speaker agrees. But to reinforce the argument to try to make others think the same, they use an unnecessary part: "The CEO of an auto<em>mobile company once said..."</em>, which is The Appeal to Authority falacy. Getting an authority fugure to back one's position.