  When you accept the idea that humans evolved without the aid or existence of a Creator you have stepped onto a dark path that leads to an ethical nightmare of meaninglessness.
From a macro view, the honest evolutionist must consider all activities of the human species as amoral. We are biological machines trapped in a contest of survival. If we create a technological utopia, it is a part of the natural process of selection. If we destroy ourselves and our planet through substances or machines we create, it is nothing more than natural selection.
The species was not fit to survive. The destruction of any species or any habitat is a natural process. All we do as humans is natural and part of the process of selection. Whether we succeed or fail as a species is irrelevant. There are those among the human species that tend to direct their energies toward the survival of the species. There are those among the human species who tend to direct their energies toward the destruction of the species.
It does not matter which group prevails. Destroyers and survivors are integral pieces of the machinery of survival and selection. We can turn our rainforests into newspaper or toilet paper. We can nuke each other until nothing is left but an uninhabitable cinder. These are natural processes carried out by the species. Environmentalists, loggers, doctors, murderers, terrorists, social workers, politicians, drug addicts... all absolutely amoral and irrelevant. To embrace evolution with all it's implications is to embrace darkness. 
