Are conservation efforts inherently wrong?

Biological conservation seems to make sense. We (as in humans) are damaging our planet and our environment, and creating a mass extinction in the process. Yet, I cannot escape the thought the evolutionary pressures are what they are. How are human-caused pressures different from outside forces, like a meteor strike? Of course, diversity in animal and plant life is important, but, by protecting species that would otherwise go extinct, are we, ourselves, selecting for weaker species?