I don't think any serious research ever posited that nature can't survive the after-effects of human activity. The issue is that if we allow motor oil, lead, m

I don't think any serious research ever posited that nature can't survive the after-effects of human activity. The issue is that if we allow motor oil, lead, mercury, etc to become part of the ecosystem, then nature will no longer be friendly to -us-. Consider that we already live in a world where one must ration their fish intake for fear of mercury poisoning.