[RWebb]

You'll be a better devil's advocate if you take an ecology course. You can then substitute knowledge for feelings. Extirpation of a species does not mean a new species will arise to "take its place" - if one does, then that will only happen over evolutionary time scales, maybe millions of years. In the meantime, you lose any benefit from the original species.

Extinction has such negative consequences that scientists have even prevented the extinction of the most dreaded diseases, including the smallpox virus, variola. It was simply erased from the wild and held 'captive" in two containment facilities.